Source code for pyspark.pandas.namespace

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"""
Wrappers around spark that correspond to common pandas functions.
"""
from typing import (
    Any,
    Callable,
    Dict,
    List,
    Optional,
    Set,
    Sized,
    Tuple,
    Type,
    Union,
    cast,
    no_type_check,
)
from collections.abc import Iterable
from datetime import tzinfo
from functools import reduce
from io import BytesIO
import json
import warnings

import numpy as np
import pandas as pd
from pandas.api.types import (  # type: ignore[attr-defined]
    is_datetime64_dtype,
    is_list_like,
)
from pandas.tseries.offsets import DateOffset
import pyarrow as pa
import pyarrow.parquet as pq

from pyspark.sql import functions as F, Column as PySparkColumn
from pyspark.sql.functions import pandas_udf
from pyspark.sql.types import (
    ByteType,
    ShortType,
    IntegerType,
    LongType,
    FloatType,
    DoubleType,
    BooleanType,
    TimestampType,
    TimestampNTZType,
    DecimalType,
    StringType,
    DateType,
    StructType,
    DataType,
)
from pyspark.sql.dataframe import DataFrame as PySparkDataFrame
from pyspark import pandas as ps
from pyspark.pandas._typing import Axis, Dtype, Label, Name
from pyspark.pandas.base import IndexOpsMixin
from pyspark.pandas.utils import (
    align_diff_frames,
    default_session,
    is_name_like_tuple,
    is_name_like_value,
    name_like_string,
    same_anchor,
    scol_for,
    validate_axis,
    log_advice,
)
from pyspark.pandas.frame import DataFrame, _reduce_spark_multi
from pyspark.pandas.internal import (
    InternalFrame,
    DEFAULT_SERIES_NAME,
    HIDDEN_COLUMNS,
    SPARK_INDEX_NAME_FORMAT,
)
from pyspark.pandas.series import Series, first_series
from pyspark.pandas.spark.utils import as_nullable_spark_type, force_decimal_precision_scale
from pyspark.pandas.indexes import Index, DatetimeIndex, TimedeltaIndex
from pyspark.pandas.indexes.multi import MultiIndex

# For Supporting Spark Connect
from pyspark.sql.utils import get_column_class

__all__ = [
    "from_pandas",
    "range",
    "read_csv",
    "read_delta",
    "read_table",
    "read_spark_io",
    "read_parquet",
    "read_clipboard",
    "read_excel",
    "read_html",
    "to_datetime",
    "date_range",
    "to_timedelta",
    "timedelta_range",
    "get_dummies",
    "concat",
    "melt",
    "isna",
    "isnull",
    "notna",
    "notnull",
    "read_sql_table",
    "read_sql_query",
    "read_sql",
    "read_json",
    "merge",
    "merge_asof",
    "to_numeric",
    "broadcast",
    "read_orc",
]


def from_pandas(pobj: Union[pd.DataFrame, pd.Series, pd.Index]) -> Union[Series, DataFrame, Index]:
    """Create a pandas-on-Spark DataFrame, Series or Index from a pandas DataFrame, Series or Index.

    This is similar to Spark's `SparkSession.createDataFrame()` with pandas DataFrame,
    but this also works with pandas Series and picks the index.

    Parameters
    ----------
    pobj : pandas.DataFrame or pandas.Series
        pandas DataFrame or Series to read.

    Returns
    -------
    Series or DataFrame
        If a pandas Series is passed in, this function returns a pandas-on-Spark Series.
        If a pandas DataFrame is passed in, this function returns a pandas-on-Spark DataFrame.
    """
    if isinstance(pobj, pd.Series):
        return Series(pobj)
    elif isinstance(pobj, pd.DataFrame):
        return DataFrame(pobj)
    elif isinstance(pobj, pd.Index):
        return DataFrame(pd.DataFrame(index=pobj)).index
    else:
        raise TypeError("Unknown data type: {}".format(type(pobj).__name__))


# built-in range
_range: Type[range] = range  # type: ignore[assignment]


[docs]def range( start: int, end: Optional[int] = None, step: int = 1, num_partitions: Optional[int] = None ) -> DataFrame: """ Create a DataFrame with some range of numbers. The resulting DataFrame has a single int64 column named `id`, containing elements in a range from ``start`` to ``end`` (exclusive) with step value ``step``. If only the first parameter (i.e. start) is specified, we treat it as the end value with the start value being 0. This is like the range function in SparkSession and is used primarily for testing. Parameters ---------- start : int the start value (inclusive) end : int, optional the end value (exclusive) step : int, optional, default 1 the incremental step num_partitions : int, optional the number of partitions of the DataFrame Returns ------- DataFrame Examples -------- When the first parameter is specified, we generate a range of values up till that number. >>> ps.range(5) id 0 0 1 1 2 2 3 3 4 4 When start, end, and step are specified: >>> ps.range(start = 100, end = 200, step = 20) id 0 100 1 120 2 140 3 160 4 180 """ sdf = default_session().range(start=start, end=end, step=step, numPartitions=num_partitions) return DataFrame(sdf)
[docs]def read_csv( path: Union[str, List[str]], sep: str = ",", header: Union[str, int, None] = "infer", names: Optional[Union[str, List[str]]] = None, index_col: Optional[Union[str, List[str]]] = None, usecols: Optional[Union[List[int], List[str], Callable[[str], bool]]] = None, dtype: Optional[Union[str, Dtype, Dict[str, Union[str, Dtype]]]] = None, nrows: Optional[int] = None, parse_dates: bool = False, quotechar: Optional[str] = None, escapechar: Optional[str] = None, comment: Optional[str] = None, encoding: Optional[str] = None, **options: Any, ) -> Union[DataFrame, Series]: """Read CSV (comma-separated) file into DataFrame or Series. Parameters ---------- path : str or list Path(s) of the CSV file(s) to be read. sep : str, default ‘,’ Delimiter to use. Non empty string. header : int, default ‘infer’ Whether to use the column names, and the start of the data. Default behavior is to infer the column names: if no names are passed the behavior is identical to `header=0` and column names are inferred from the first line of the file, if column names are passed explicitly then the behavior is identical to `header=None`. Explicitly pass `header=0` to be able to replace existing names names : str or array-like, optional List of column names to use. If file contains no header row, then you should explicitly pass `header=None`. Duplicates in this list will cause an error to be issued. If a string is given, it should be a DDL-formatted string in Spark SQL, which is preferred to avoid schema inference for better performance. index_col: str or list of str, optional, default: None Index column of table in Spark. usecols : list-like or callable, optional Return a subset of the columns. If list-like, all elements must either be positional (i.e. integer indices into the document columns) or strings that correspond to column names provided either by the user in names or inferred from the document header row(s). If callable, the callable function will be evaluated against the column names, returning names where the callable function evaluates to `True`. dtype : Type name or dict of column -> type, default None Data type for data or columns. E.g. {‘a’: np.float64, ‘b’: np.int32} Use str or object together with suitable na_values settings to preserve and not interpret dtype. nrows : int, default None Number of rows to read from the CSV file. parse_dates : boolean or list of ints or names or list of lists or dict, default `False`. Currently only `False` is allowed. quotechar : str (length 1), optional The character used to denote the start and end of a quoted item. Quoted items can include the delimiter and it will be ignored. escapechar : str (length 1), default None One-character string used to escape other characters. comment: str, optional Indicates the line should not be parsed. encoding: str, optional Indicates the encoding to read file options : dict All other options passed directly into Spark's data source. Returns ------- DataFrame or Series See Also -------- DataFrame.to_csv : Write DataFrame to a comma-separated values (csv) file. Examples -------- >>> ps.read_csv('data.csv') # doctest: +SKIP Load multiple CSV files as a single DataFrame: >>> ps.read_csv(['data-01.csv', 'data-02.csv']) # doctest: +SKIP """ # For latin-1 encoding is same as iso-8859-1, that's why its mapped to iso-8859-1. encoding_mapping = {"latin-1": "iso-8859-1"} if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") if parse_dates is not False: raise ValueError("parse_dates can only be `False`: %s" % parse_dates) if usecols is not None and not callable(usecols): usecols = list(usecols) # type: ignore[assignment] if usecols is None or callable(usecols) or len(usecols) > 0: reader = default_session().read reader.option("inferSchema", True) reader.option("sep", sep) if header == "infer": header = 0 if names is None else None if header == 0: reader.option("header", True) elif header is None: reader.option("header", False) else: raise ValueError("Unknown header argument {}".format(header)) if quotechar is not None: reader.option("quote", quotechar) if escapechar is not None: reader.option("escape", escapechar) if comment is not None: if not isinstance(comment, str) or len(comment) != 1: raise ValueError("Only length-1 comment characters supported") reader.option("comment", comment) reader.options(**options) if encoding is not None: reader.option("encoding", encoding_mapping.get(encoding, encoding)) column_labels: Dict[Any, str] if isinstance(names, str): sdf = reader.schema(names).csv(path) column_labels = {col: col for col in sdf.columns} else: sdf = reader.csv(path) if is_list_like(names): names = list(names) if len(set(names)) != len(names): raise ValueError("Found non-unique column index") if len(names) != len(sdf.columns): raise ValueError( "The number of names [%s] does not match the number " "of columns [%d]. Try names by a Spark SQL DDL-formatted " "string." % (len(sdf.schema), len(names)) ) column_labels = dict(zip(names, sdf.columns)) elif header is None: column_labels = dict(enumerate(sdf.columns)) else: column_labels = {col: col for col in sdf.columns} if usecols is not None: missing: List[Union[int, str]] if callable(usecols): column_labels = { label: col for label, col in column_labels.items() if usecols(label) } missing = [] elif all(isinstance(col, int) for col in usecols): usecols_ints = cast(List[int], usecols) new_column_labels = { label: col for i, (label, col) in enumerate(column_labels.items()) if i in usecols_ints } missing = [ col for col in usecols_ints if ( col >= len(column_labels) or list(column_labels)[col] not in new_column_labels ) ] column_labels = new_column_labels elif all(isinstance(col, str) for col in usecols): new_column_labels = { label: col for label, col in column_labels.items() if label in usecols } missing = [col for col in usecols if col not in new_column_labels] column_labels = new_column_labels else: raise ValueError( "'usecols' must either be list-like of all strings, " "all unicode, all integers or a callable." ) if len(missing) > 0: raise ValueError( "Usecols do not match columns, columns expected but not " "found: %s" % missing ) if len(column_labels) > 0: sdf = sdf.select([scol_for(sdf, col) for col in column_labels.values()]) else: sdf = default_session().createDataFrame([], schema=StructType()) else: sdf = default_session().createDataFrame([], schema=StructType()) column_labels = {} if nrows is not None: sdf = sdf.limit(nrows) index_spark_column_names: List[str] index_names: List[Label] if index_col is not None: if isinstance(index_col, (str, int)): index_col = [index_col] for col in index_col: if col not in column_labels: raise KeyError(col) index_spark_column_names = [column_labels[col] for col in index_col] index_names = [(col,) for col in index_col] column_labels = { label: col for label, col in column_labels.items() if label not in index_col } else: log_advice( "If `index_col` is not specified for `read_csv`, " "the default index is attached which can cause additional overhead." ) index_spark_column_names = [] index_names = [] psdf: DataFrame = DataFrame( InternalFrame( spark_frame=sdf, index_spark_columns=[scol_for(sdf, col) for col in index_spark_column_names], index_names=index_names, column_labels=[ label if is_name_like_tuple(label) else (label,) for label in column_labels ], data_spark_columns=[scol_for(sdf, col) for col in column_labels.values()], ) ) if dtype is not None: if isinstance(dtype, dict): for col, tpe in dtype.items(): psdf[col] = psdf[col].astype(tpe) else: for col in psdf.columns: psdf[col] = psdf[col].astype(dtype) return psdf
[docs]def read_json( path: str, lines: bool = True, index_col: Optional[Union[str, List[str]]] = None, **options: Any ) -> DataFrame: """ Convert a JSON string to DataFrame. Parameters ---------- path : string File path lines : bool, default True Read the file as a JSON object per line. It should be always True for now. index_col : str or list of str, optional, default: None Index column of table in Spark. options : dict All other options passed directly into Spark's data source. Examples -------- >>> df = ps.DataFrame([['a', 'b'], ['c', 'd']], ... columns=['col 1', 'col 2']) >>> df.to_json(path=r'%s/read_json/foo.json' % path, num_files=1) >>> ps.read_json( ... path=r'%s/read_json/foo.json' % path ... ).sort_values(by="col 1") col 1 col 2 0 a b 1 c d >>> df.to_json(path=r'%s/read_json/foo.json' % path, num_files=1, lineSep='___') >>> ps.read_json( ... path=r'%s/read_json/foo.json' % path, lineSep='___' ... ).sort_values(by="col 1") col 1 col 2 0 a b 1 c d You can preserve the index in the roundtrip as below. >>> df.to_json(path=r'%s/read_json/bar.json' % path, num_files=1, index_col="index") >>> ps.read_json( ... path=r'%s/read_json/bar.json' % path, index_col="index" ... ).sort_values(by="col 1") # doctest: +NORMALIZE_WHITESPACE col 1 col 2 index 0 a b 1 c d """ if index_col is None: log_advice( "If `index_col` is not specified for `read_json`, " "the default index is attached which can cause additional overhead." ) if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") if not lines: raise NotImplementedError("lines=False is not implemented yet.") return read_spark_io(path, format="json", index_col=index_col, **options)
[docs]def read_delta( path: str, version: Optional[str] = None, timestamp: Optional[str] = None, index_col: Optional[Union[str, List[str]]] = None, **options: Any, ) -> DataFrame: """ Read a Delta Lake table on some file system and return a DataFrame. If the Delta Lake table is already stored in the catalog (aka the metastore), use 'read_table'. Parameters ---------- path : string Path to the Delta Lake table. version : string, optional Specifies the table version (based on Delta's internal transaction version) to read from, using Delta's time travel feature. This sets Delta's 'versionAsOf' option. Note that this parameter and `timestamp` parameter cannot be used together, otherwise it will raise a `ValueError`. timestamp : string, optional Specifies the table version (based on timestamp) to read from, using Delta's time travel feature. This must be a valid date or timestamp string in Spark, and sets Delta's 'timestampAsOf' option. Note that this parameter and `version` parameter cannot be used together, otherwise it will raise a `ValueError`. index_col : str or list of str, optional, default: None Index column of table in Spark. options Additional options that can be passed onto Delta. Returns ------- DataFrame See Also -------- DataFrame.to_delta read_table read_spark_io read_parquet Examples -------- >>> ps.range(1).to_delta('%s/read_delta/foo' % path) # doctest: +SKIP >>> ps.read_delta('%s/read_delta/foo' % path) # doctest: +SKIP id 0 0 >>> ps.range(10, 15, num_partitions=1).to_delta('%s/read_delta/foo' % path, ... mode='overwrite') # doctest: +SKIP >>> ps.read_delta('%s/read_delta/foo' % path) # doctest: +SKIP id 0 10 1 11 2 12 3 13 4 14 >>> ps.read_delta('%s/read_delta/foo' % path, version=0) # doctest: +SKIP id 0 0 You can preserve the index in the roundtrip as below. >>> ps.range(10, 15, num_partitions=1).to_delta( ... '%s/read_delta/bar' % path, index_col="index") # doctest: +SKIP >>> ps.read_delta('%s/read_delta/bar' % path, index_col="index") # doctest: +SKIP id index 0 10 1 11 2 12 3 13 4 14 """ if index_col is None: log_advice( "If `index_col` is not specified for `read_delta`, " "the default index is attached which can cause additional overhead." ) if version is not None and timestamp is not None: raise ValueError("version and timestamp cannot be used together.") if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") if version is not None: options["versionAsOf"] = version if timestamp is not None: options["timestampAsOf"] = timestamp return read_spark_io(path, format="delta", index_col=index_col, **options)
[docs]def read_table(name: str, index_col: Optional[Union[str, List[str]]] = None) -> DataFrame: """ Read a Spark table and return a DataFrame. Parameters ---------- name : string Table name in Spark. index_col : str or list of str, optional, default: None Index column of table in Spark. Returns ------- DataFrame See Also -------- DataFrame.to_table read_delta read_parquet read_spark_io Examples -------- >>> ps.range(1).to_table('%s.my_table' % db) >>> ps.read_table('%s.my_table' % db) id 0 0 >>> ps.range(1).to_table('%s.my_table' % db, index_col="index") >>> ps.read_table('%s.my_table' % db, index_col="index") # doctest: +NORMALIZE_WHITESPACE id index 0 0 """ if index_col is None: log_advice( "If `index_col` is not specified for `read_table`, " "the default index is attached which can cause additional overhead." ) sdf = default_session().read.table(name) index_spark_columns, index_names = _get_index_map(sdf, index_col) return DataFrame( InternalFrame( spark_frame=sdf, index_spark_columns=index_spark_columns, index_names=index_names ) )
[docs]def read_spark_io( path: Optional[str] = None, format: Optional[str] = None, schema: Union[str, "StructType"] = None, index_col: Optional[Union[str, List[str]]] = None, **options: Any, ) -> DataFrame: """Load a DataFrame from a Spark data source. Parameters ---------- path : string, optional Path to the data source. format : string, optional Specifies the output data source format. Some common ones are: - 'delta' - 'parquet' - 'orc' - 'json' - 'csv' schema : string or StructType, optional Input schema. If none, Spark tries to infer the schema automatically. The schema can either be a Spark StructType, or a DDL-formatted string like `col0 INT, col1 DOUBLE`. index_col : str or list of str, optional, default: None Index column of table in Spark. options : dict All other options passed directly into Spark's data source. See Also -------- DataFrame.read_table DataFrame.read_delta DataFrame.read_parquet Examples -------- >>> ps.range(1).spark.to_spark_io('%s/read_spark_io/data.parquet' % path) >>> ps.read_spark_io( ... '%s/read_spark_io/data.parquet' % path, format='parquet', schema='id long') id 0 0 >>> ps.range(10, 15, num_partitions=1).spark.to_spark_io('%s/read_spark_io/data.json' % path, ... format='json', lineSep='__') >>> ps.read_spark_io( ... '%s/read_spark_io/data.json' % path, format='json', schema='id long', lineSep='__') id 0 10 1 11 2 12 3 13 4 14 You can preserve the index in the roundtrip as below. >>> ps.range(10, 15, num_partitions=1).spark.to_spark_io('%s/read_spark_io/data.orc' % path, ... format='orc', index_col="index") >>> ps.read_spark_io( ... path=r'%s/read_spark_io/data.orc' % path, format="orc", index_col="index") ... # doctest: +NORMALIZE_WHITESPACE id index 0 10 1 11 2 12 3 13 4 14 """ if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") sdf = default_session().read.load(path=path, format=format, schema=schema, **options) index_spark_columns, index_names = _get_index_map(sdf, index_col) return DataFrame( InternalFrame( spark_frame=sdf, index_spark_columns=index_spark_columns, index_names=index_names ) )
[docs]def read_parquet( path: str, columns: Optional[List[str]] = None, index_col: Optional[List[str]] = None, pandas_metadata: bool = False, **options: Any, ) -> DataFrame: """Load a parquet object from the file path, returning a DataFrame. Parameters ---------- path : string File path columns : list, default=None If not None, only these columns will be read from the file. index_col : str or list of str, optional, default: None Index column of table in Spark. pandas_metadata : bool, default: False If True, try to respect the metadata if the Parquet file is written from pandas. options : dict All other options passed directly into Spark's data source. Returns ------- DataFrame See Also -------- DataFrame.to_parquet DataFrame.read_table DataFrame.read_delta DataFrame.read_spark_io Examples -------- >>> ps.range(1).to_parquet('%s/read_spark_io/data.parquet' % path) >>> ps.read_parquet('%s/read_spark_io/data.parquet' % path, columns=['id']) id 0 0 You can preserve the index in the roundtrip as below. >>> ps.range(1).to_parquet('%s/read_spark_io/data.parquet' % path, index_col="index") >>> ps.read_parquet('%s/read_spark_io/data.parquet' % path, columns=['id'], index_col="index") ... # doctest: +NORMALIZE_WHITESPACE id index 0 0 """ if index_col is None: log_advice( "If `index_col` is not specified for `read_parquet`, " "the default index is attached which can cause additional overhead." ) if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") if columns is not None: columns = list(columns) index_names = None if index_col is None and pandas_metadata: # Try to read pandas metadata @pandas_udf( # type: ignore[call-overload] "index_col array<string>, index_names array<string>" ) def read_index_metadata(pser: pd.Series) -> pd.DataFrame: binary = pser.iloc[0] metadata = pq.ParquetFile(pa.BufferReader(binary)).metadata.metadata if b"pandas" in metadata: pandas_metadata = json.loads(metadata[b"pandas"].decode("utf8")) if all(isinstance(col, str) for col in pandas_metadata["index_columns"]): index_col = [] index_names = [] for col in pandas_metadata["index_columns"]: index_col.append(col) for column in pandas_metadata["columns"]: if column["field_name"] == col: index_names.append(column["name"]) break else: index_names.append(None) return pd.DataFrame({"index_col": [index_col], "index_names": [index_names]}) return pd.DataFrame({"index_col": [None], "index_names": [None]}) index_col, index_names = ( default_session() .read.format("binaryFile") .load(path) .limit(1) .select(read_index_metadata("content").alias("index_metadata")) .select("index_metadata.*") .head() ) psdf = read_spark_io(path=path, format="parquet", options=options, index_col=index_col) if columns is not None: new_columns = [c for c in columns if c in psdf.columns] if len(new_columns) > 0: psdf = psdf[new_columns] else: sdf = default_session().createDataFrame([], schema=StructType()) index_spark_columns, index_names = _get_index_map(sdf, index_col) psdf = DataFrame( InternalFrame( spark_frame=sdf, index_spark_columns=index_spark_columns, index_names=index_names, ) ) if index_names is not None: psdf.index.names = index_names return psdf
[docs]def read_clipboard(sep: str = r"\s+", **kwargs: Any) -> DataFrame: r""" Read text from clipboard and pass to read_csv. See read_csv for the full argument list Parameters ---------- sep : str, default '\s+' A string or regex delimiter. The default of '\s+' denotes one or more whitespace characters. See Also -------- DataFrame.to_clipboard : Write text out to clipboard. Returns ------- parsed : DataFrame """ return cast(DataFrame, from_pandas(pd.read_clipboard(sep, **kwargs)))
[docs]def read_excel( io: Union[str, Any], sheet_name: Union[str, int, List[Union[str, int]], None] = 0, header: Union[int, List[int]] = 0, names: Optional[List] = None, index_col: Optional[List[int]] = None, usecols: Optional[Union[int, str, List[Union[int, str]], Callable[[str], bool]]] = None, dtype: Optional[Dict[str, Union[str, Dtype]]] = None, engine: Optional[str] = None, converters: Optional[Dict] = None, true_values: Optional[Any] = None, false_values: Optional[Any] = None, skiprows: Optional[Union[int, List[int]]] = None, nrows: Optional[int] = None, na_values: Optional[Any] = None, keep_default_na: bool = True, verbose: bool = False, parse_dates: Union[bool, List, Dict] = False, date_parser: Optional[Callable] = None, thousands: Optional[str] = None, comment: Optional[str] = None, skipfooter: int = 0, **kwds: Any, ) -> Union[DataFrame, Series, Dict[str, Union[DataFrame, Series]]]: """ Read an Excel file into a pandas-on-Spark DataFrame or Series. Support both `xls` and `xlsx` file extensions from a local filesystem or URL. Support an option to read a single sheet or a list of sheets. Parameters ---------- io : str, file descriptor, pathlib.Path, ExcelFile or xlrd.Book The string could be a URL. The value URL must be available in Spark's DataFrameReader. .. note:: If the underlying Spark is below 3.0, the parameter as a string is not supported. You can use `ps.from_pandas(pd.read_excel(...))` as a workaround. sheet_name : str, int, list, or None, default 0 Strings are used for sheet names. Integers are used in zero-indexed sheet positions. Lists of strings/integers are used to request multiple sheets. Specify None to get all sheets. Available cases: * Defaults to ``0``: 1st sheet as a `DataFrame` * ``1``: 2nd sheet as a `DataFrame` * ``"Sheet1"``: Load sheet with name "Sheet1" * ``[0, 1, "Sheet5"]``: Load first, second and sheet named "Sheet5" as a dict of `DataFrame` * None: All sheets. header : int, list of int, default 0 Row (0-indexed) to use for the column labels of the parsed DataFrame. If a list of integers is passed those row positions will be combined into a ``MultiIndex``. Use None if there is no header. names : array-like, default None List of column names to use. If file contains no header row, then you should explicitly pass header=None. index_col : int, list of int, default None Column (0-indexed) to use as the row labels of the DataFrame. Pass None if there is no such column. If a list is passed, those columns will be combined into a ``MultiIndex``. If a subset of data is selected with ``usecols``, index_col is based on the subset. usecols : int, str, list-like, or callable default None Return a subset of the columns. * If None, then parse all columns. * If str, then indicates comma separated list of Excel column letters and column ranges (e.g. "A:E" or "A,C,E:F"). Ranges are inclusive of both sides. * If list of int, then indicates list of column numbers to be parsed. * If list of string, then indicates list of column names to be parsed. * If callable, then evaluate each column name against it and parse the column if the callable returns ``True``. dtype : Type name or dict of column -> type, default None Data type for data or columns. E.g. {'a': np.float64, 'b': np.int32} Use `object` to preserve data as stored in Excel and not interpret dtype. If converters are specified, they will be applied INSTEAD of dtype conversion. engine : str, default None If io is not a buffer or path, this must be set to identify io. Acceptable values are None or xlrd. converters : dict, default None Dict of functions for converting values in certain columns. Keys can either be integers or column labels, values are functions that take one input argument, the Excel cell content, and return the transformed content. true_values : list, default None Values to consider as True. false_values : list, default None Values to consider as False. skiprows : list-like Rows to skip at the beginning (0-indexed). nrows : int, default None Number of rows to parse. na_values : scalar, str, list-like, or dict, default None Additional strings to recognize as NA/NaN. If dict passed, specific per-column NA values. By default the following values are interpreted as NaN. keep_default_na : bool, default True If na_values are specified and keep_default_na is False the default NaN values are overridden, otherwise they're appended to. verbose : bool, default False Indicate number of NA values placed in non-numeric columns. parse_dates : bool, list-like, or dict, default False The behavior is as follows: * bool. If True -> try parsing the index. * list of int or names. e.g. If [1, 2, 3] -> try parsing columns 1, 2, 3 each as a separate date column. * list of lists. e.g. If [[1, 3]] -> combine columns 1 and 3 and parse as a single date column. * dict, e.g. {{'foo' : [1, 3]}} -> parse columns 1, 3 as date and call result 'foo' If a column or index contains an unparseable date, the entire column or index will be returned unaltered as an object data type. For non-standard datetime parsing, use ``pd.to_datetime`` after ``pd.read_csv`` Note: A fast-path exists for iso8601-formatted dates. date_parser : function, optional Function to use for converting a sequence of string columns to an array of datetime instances. The default uses ``dateutil.parser.parser`` to do the conversion. pandas-on-Spark will try to call `date_parser` in three different ways, advancing to the next if an exception occurs: 1) Pass one or more arrays (as defined by `parse_dates`) as arguments; 2) concatenate (row-wise) the string values from the columns defined by `parse_dates` into a single array and pass that; and 3) call `date_parser` once for each row using one or more strings (corresponding to the columns defined by `parse_dates`) as arguments. thousands : str, default None Thousands separator for parsing string columns to numeric. Note that this parameter is only necessary for columns stored as TEXT in Excel, any numeric columns will automatically be parsed, regardless of display format. comment : str, default None Comments out remainder of line. Pass a character or characters to this argument to indicate comments in the input file. Any data between the comment string and the end of the current line is ignored. skipfooter : int, default 0 Rows at the end to skip (0-indexed). **kwds : optional Optional keyword arguments can be passed to ``TextFileReader``. Returns ------- DataFrame or dict of DataFrames DataFrame from the passed in Excel file. See notes in sheet_name argument for more information on when a dict of DataFrames is returned. See Also -------- DataFrame.to_excel : Write DataFrame to an Excel file. DataFrame.to_csv : Write DataFrame to a comma-separated values (csv) file. read_csv : Read a comma-separated values (csv) file into DataFrame. Examples -------- The file can be read using the file name as string or an open file object: >>> ps.read_excel('tmp.xlsx', index_col=0) # doctest: +SKIP Name Value 0 string1 1 1 string2 2 2 #Comment 3 >>> ps.read_excel(open('tmp.xlsx', 'rb'), ... sheet_name='Sheet3') # doctest: +SKIP Unnamed: 0 Name Value 0 0 string1 1 1 1 string2 2 2 2 #Comment 3 Index and header can be specified via the `index_col` and `header` arguments >>> ps.read_excel('tmp.xlsx', index_col=None, header=None) # doctest: +SKIP 0 1 2 0 NaN Name Value 1 0.0 string1 1 2 1.0 string2 2 3 2.0 #Comment 3 Column types are inferred but can be explicitly specified >>> ps.read_excel('tmp.xlsx', index_col=0, ... dtype={'Name': str, 'Value': float}) # doctest: +SKIP Name Value 0 string1 1.0 1 string2 2.0 2 #Comment 3.0 True, False, and NA values, and thousands separators have defaults, but can be explicitly specified, too. Supply the values you would like as strings or lists of strings! >>> ps.read_excel('tmp.xlsx', index_col=0, ... na_values=['string1', 'string2']) # doctest: +SKIP Name Value 0 None 1 1 None 2 2 #Comment 3 Comment lines in the excel input file can be skipped using the `comment` kwarg >>> ps.read_excel('tmp.xlsx', index_col=0, comment='#') # doctest: +SKIP Name Value 0 string1 1.0 1 string2 2.0 2 None NaN """ def pd_read_excel( io_or_bin: Any, sn: Union[str, int, List[Union[str, int]], None] ) -> pd.DataFrame: return pd.read_excel( io=BytesIO(io_or_bin) if isinstance(io_or_bin, (bytes, bytearray)) else io_or_bin, sheet_name=sn, header=header, names=names, index_col=index_col, usecols=usecols, dtype=dtype, engine=engine, converters=converters, true_values=true_values, false_values=false_values, skiprows=skiprows, nrows=nrows, na_values=na_values, keep_default_na=keep_default_na, verbose=verbose, parse_dates=parse_dates, # type: ignore[arg-type] date_parser=date_parser, thousands=thousands, comment=comment, skipfooter=skipfooter, **kwds, ) if isinstance(io, str): # 'binaryFile' format is available since Spark 3.0.0. binaries = default_session().read.format("binaryFile").load(io).select("content").head(2) io_or_bin = binaries[0][0] single_file = len(binaries) == 1 else: io_or_bin = io single_file = True pdf_or_psers = pd_read_excel(io_or_bin, sn=sheet_name) if single_file: if isinstance(pdf_or_psers, dict): return { sn: cast(Union[DataFrame, Series], from_pandas(pdf_or_pser)) for sn, pdf_or_pser in pdf_or_psers.items() } else: return cast(Union[DataFrame, Series], from_pandas(pdf_or_psers)) else: def read_excel_on_spark( pdf_or_pser: Union[pd.DataFrame, pd.Series], sn: Union[str, int, List[Union[str, int]], None], ) -> Union[DataFrame, Series]: if isinstance(pdf_or_pser, pd.Series): pdf = pdf_or_pser.to_frame() else: pdf = pdf_or_pser psdf = cast(DataFrame, from_pandas(pdf)) return_schema = force_decimal_precision_scale( as_nullable_spark_type(psdf._internal.spark_frame.drop(*HIDDEN_COLUMNS).schema) ) def output_func(pdf: pd.DataFrame) -> pd.DataFrame: pdf = pd.concat([pd_read_excel(bin, sn=sn) for bin in pdf[pdf.columns[0]]]) reset_index = pdf.reset_index() for name, col in reset_index.items(): dt = col.dtype if is_datetime64_dtype(dt) or isinstance(dt, pd.DatetimeTZDtype): continue reset_index[name] = col.replace({np.nan: None}) pdf = reset_index # Just positionally map the column names to given schema's. return pdf.rename(columns=dict(zip(pdf.columns, return_schema.names))) sdf = ( default_session() .read.format("binaryFile") .load(io) .select("content") .mapInPandas(lambda iterator: map(output_func, iterator), schema=return_schema) ) return DataFrame(psdf._internal.with_new_sdf(sdf)) if isinstance(pdf_or_psers, dict): return { sn: read_excel_on_spark(pdf_or_pser, sn) for sn, pdf_or_pser in pdf_or_psers.items() } else: return read_excel_on_spark(pdf_or_psers, sheet_name)
[docs]def read_html( io: Union[str, Any], match: str = ".+", flavor: Optional[str] = None, header: Optional[Union[int, List[int]]] = None, index_col: Optional[Union[int, List[int]]] = None, skiprows: Optional[Union[int, List[int], slice]] = None, attrs: Optional[Dict[str, str]] = None, parse_dates: bool = False, thousands: str = ",", encoding: Optional[str] = None, decimal: str = ".", converters: Optional[Dict] = None, na_values: Optional[Any] = None, keep_default_na: bool = True, displayed_only: bool = True, ) -> List[DataFrame]: r"""Read HTML tables into a ``list`` of ``DataFrame`` objects. Parameters ---------- io : str or file-like A URL, a file-like object, or a raw string containing HTML. Note that lxml only accepts the http, FTP and file URL protocols. If you have a URL that starts with ``'https'`` you might try removing the ``'s'``. .. deprecated:: 4.0.0 Passing html literal strings is deprecated. Wrap literal string/bytes input in io.StringIO/io.BytesIO instead. match : str or compiled regular expression, optional The set of tables containing text matching this regex or string will be returned. Unless the HTML is extremely simple you will probably need to pass a non-empty string here. Defaults to '.+' (match any non-empty string). The default value will return all tables contained on a page. This value is converted to a regular expression so that there is consistent behavior between Beautiful Soup and lxml. flavor : str or None, container of strings The parsing engine to use. 'bs4' and 'html5lib' are synonymous with each other, they are both there for backwards compatibility. The default of ``None`` tries to use ``lxml`` to parse and if that fails it falls back on ``bs4`` + ``html5lib``. header : int or list-like or None, optional The row (or list of rows for a :class:`~ps.MultiIndex`) to use to make the columns headers. index_col : int or list-like or None, optional The column (or list of columns) to use to create the index. skiprows : int or list-like or slice or None, optional 0-based. Number of rows to skip after parsing the column integer. If a sequence of integers or a slice is given, will skip the rows indexed by that sequence. Note that a single element sequence means 'skip the nth row' whereas an integer means 'skip n rows'. attrs : dict or None, optional This is a dictionary of attributes that you can pass to use to identify the table in the HTML. These are not checked for validity before being passed to lxml or Beautiful Soup. However, these attributes must be valid HTML table attributes to work correctly. For example, :: attrs = {'id': 'table'} is a valid attribute dictionary because the 'id' HTML tag attribute is a valid HTML attribute for *any* HTML tag as per `this document <http://www.w3.org/TR/html-markup/global-attributes.html>`__. :: attrs = {'asdf': 'table'} is *not* a valid attribute dictionary because 'asdf' is not a valid HTML attribute even if it is a valid XML attribute. Valid HTML 4.01 table attributes can be found `here <http://www.w3.org/TR/REC-html40/struct/tables.html#h-11.2>`__. A working draft of the HTML 5 spec can be found `here <http://www.w3.org/TR/html-markup/table.html>`__. It contains the latest information on table attributes for the modern web. parse_dates : bool, optional See :func:`~ps.read_csv` for more details. thousands : str, optional Separator to use to parse thousands. Defaults to ``','``. encoding : str or None, optional The encoding used to decode the web page. Defaults to ``None``.``None`` preserves the previous encoding behavior, which depends on the underlying parser library (e.g., the parser library will try to use the encoding provided by the document). decimal : str, default '.' Character to recognize as decimal point (example: use ',' for European data). converters : dict, default None Dict of functions for converting values in certain columns. Keys can either be integers or column labels, values are functions that take one input argument, the cell (not column) content, and return the transformed content. na_values : iterable, default None Custom NA values keep_default_na : bool, default True If na_values are specified and keep_default_na is False the default NaN values are overridden, otherwise they're appended to displayed_only : bool, default True Whether elements with "display: none" should be parsed Returns ------- dfs : list of DataFrames See Also -------- read_csv DataFrame.to_html """ pdfs = pd.read_html( io=io, match=match, flavor=flavor, header=header, index_col=index_col, skiprows=skiprows, attrs=attrs, parse_dates=parse_dates, thousands=thousands, encoding=encoding, decimal=decimal, converters=converters, na_values=na_values, keep_default_na=keep_default_na, displayed_only=displayed_only, ) return cast(List[DataFrame], [from_pandas(pdf) for pdf in pdfs])
# TODO: add `coerce_float` and 'parse_dates' parameters
[docs]def read_sql_table( table_name: str, con: str, schema: Optional[str] = None, index_col: Optional[Union[str, List[str]]] = None, columns: Optional[Union[str, List[str]]] = None, **options: Any, ) -> DataFrame: """ Read SQL database table into a DataFrame. Given a table name and a JDBC URI, returns a DataFrame. Parameters ---------- table_name : str Name of SQL table in database. con : str A JDBC URI could be provided as str. .. note:: The URI must be JDBC URI instead of Python's database URI. schema : str, default None Name of SQL schema in database to query (if database flavor supports this). Uses default schema if None (default). index_col : str or list of str, optional, default: None Column(s) to set as index(MultiIndex). columns : list, default None List of column names to select from SQL table. options : dict All other options passed directly into Spark's JDBC data source. Returns ------- DataFrame A SQL table is returned as two-dimensional data structure with labeled axes. See Also -------- read_sql_query : Read SQL query into a DataFrame. read_sql : Read SQL query or database table into a DataFrame. Examples -------- >>> ps.read_sql_table('table_name', 'jdbc:postgresql:db_name') # doctest: +SKIP """ if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") reader = default_session().read reader.option("dbtable", table_name) reader.option("url", con) if schema is not None: reader.schema(schema) reader.options(**options) sdf = reader.format("jdbc").load() index_spark_columns, index_names = _get_index_map(sdf, index_col) psdf: DataFrame = DataFrame( InternalFrame( spark_frame=sdf, index_spark_columns=index_spark_columns, index_names=index_names ) ) if columns is not None: if isinstance(columns, str): columns = [columns] psdf = psdf[columns] return psdf
# TODO: add `coerce_float`, `params`, and 'parse_dates' parameters
[docs]def read_sql_query( sql: str, con: str, index_col: Optional[Union[str, List[str]]] = None, **options: Any ) -> DataFrame: """Read SQL query into a DataFrame. Returns a DataFrame corresponding to the result set of the query string. Optionally provide an `index_col` parameter to use one of the columns as the index, otherwise default index will be used. .. note:: Some database might hit the issue of Spark: SPARK-27596 Parameters ---------- sql : string SQL query SQL query to be executed. con : str A JDBC URI could be provided as str. .. note:: The URI must be JDBC URI instead of Python's database URI. index_col : string or list of strings, optional, default: None Column(s) to set as index(MultiIndex). options : dict All other options passed directly into Spark's JDBC data source. Returns ------- DataFrame See Also -------- read_sql_table : Read SQL database table into a DataFrame. read_sql Examples -------- >>> ps.read_sql_query('SELECT * FROM table_name', 'jdbc:postgresql:db_name') # doctest: +SKIP """ if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") reader = default_session().read reader.option("query", sql) reader.option("url", con) reader.options(**options) sdf = reader.format("jdbc").load() index_spark_columns, index_names = _get_index_map(sdf, index_col) return DataFrame( InternalFrame( spark_frame=sdf, index_spark_columns=index_spark_columns, index_names=index_names ) )
# TODO: add `coerce_float`, `params`, and 'parse_dates' parameters
[docs]def read_sql( sql: str, con: str, index_col: Optional[Union[str, List[str]]] = None, columns: Optional[Union[str, List[str]]] = None, **options: Any, ) -> DataFrame: """ Read SQL query or database table into a DataFrame. This function is a convenience wrapper around ``read_sql_table`` and ``read_sql_query`` (for backward compatibility). It will delegate to the specific function depending on the provided input. A SQL query will be routed to ``read_sql_query``, while a database table name will be routed to ``read_sql_table``. Note that the delegated function might have more specific notes about their functionality not listed here. .. note:: Some database might hit the issue of Spark: SPARK-27596 Parameters ---------- sql : string SQL query to be executed or a table name. con : str A JDBC URI could be provided as str. .. note:: The URI must be JDBC URI instead of Python's database URI. index_col : string or list of strings, optional, default: None Column(s) to set as index(MultiIndex). columns : list, default: None List of column names to select from SQL table (only used when reading a table). options : dict All other options passed directly into Spark's JDBC data source. Returns ------- DataFrame See Also -------- read_sql_table : Read SQL database table into a DataFrame. read_sql_query : Read SQL query into a DataFrame. Examples -------- >>> ps.read_sql('table_name', 'jdbc:postgresql:db_name') # doctest: +SKIP >>> ps.read_sql('SELECT * FROM table_name', 'jdbc:postgresql:db_name') # doctest: +SKIP """ if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") striped = sql.strip() if " " not in striped: # TODO: identify the table name or not more precisely. return read_sql_table(sql, con, index_col=index_col, columns=columns, **options) else: return read_sql_query(sql, con, index_col=index_col, **options)
[docs]@no_type_check def to_datetime( arg, errors: str = "raise", format: Optional[str] = None, unit: Optional[str] = None, infer_datetime_format: bool = False, origin: str = "unix", ): """ Convert argument to datetime. Parameters ---------- arg : integer, float, string, datetime, list, tuple, 1-d array, Series or DataFrame/dict-like errors : {'ignore', 'raise', 'coerce'}, default 'raise' - If 'raise', then invalid parsing will raise an exception - If 'coerce', then invalid parsing will be set as NaT - If 'ignore', then invalid parsing will return the input format : string, default None strftime to parse time, eg "%d/%m/%Y", note that "%f" will parse all the way up to nanoseconds. unit : string, default None unit of the arg (D,s,ms,us,ns) denote the unit, which is an integer or float number. This will be based off the origin. Example, with unit='ms' and origin='unix' (the default), this would calculate the number of milliseconds to the unix epoch start. infer_datetime_format : boolean, default False If True and no `format` is given, attempt to infer the format of the datetime strings, and if it can be inferred, switch to a faster method of parsing them. In some cases this can increase the parsing speed by ~5-10x. origin : scalar, default 'unix' Define the reference date. The numeric values would be parsed as number of units (defined by `unit`) since this reference date. - If 'unix' (or POSIX) time; origin is set to 1970-01-01. - If 'julian', unit must be 'D', and origin is set to beginning of Julian Calendar. Julian day number 0 is assigned to the day starting at noon on January 1, 4713 BC. - If Timestamp convertible, origin is set to Timestamp identified by origin. Returns ------- ret : datetime if parsing succeeded. Return type depends on input: - list-like: DatetimeIndex - Series: Series of datetime64 dtype - scalar: Timestamp In case when it is not possible to return designated types (e.g. when any element of input is before Timestamp.min or after Timestamp.max) return will have datetime.datetime type (or corresponding array/Series). Examples -------- Assembling a datetime from multiple columns of a DataFrame. The keys can be common abbreviations like ['year', 'month', 'day', 'minute', 'second', 'ms', 'us', 'ns']) or plurals of the same >>> df = ps.DataFrame({'year': [2015, 2016], ... 'month': [2, 3], ... 'day': [4, 5]}) >>> ps.to_datetime(df) 0 2015-02-04 1 2016-03-05 dtype: datetime64[ns] If a date does not meet the `timestamp limitations <http://pandas.pydata.org/pandas-docs/stable/timeseries.html #timeseries-timestamp-limits>`_, passing errors='ignore' will return the original input instead of raising any exception. Passing errors='coerce' will force an out-of-bounds date to NaT, in addition to forcing non-dates (or non-parseable dates) to NaT. >>> ps.to_datetime('13000101', format='%Y%m%d', errors='ignore') # doctest: +SKIP datetime.datetime(1300, 1, 1, 0, 0) >>> ps.to_datetime('13000101', format='%Y%m%d', errors='coerce') NaT Passing infer_datetime_format=True can often-times speedup a parsing if its not an ISO8601 format exactly, but in a regular format. >>> s = ps.Series(['3/11/2000', '3/12/2000', '3/13/2000'] * 1000) >>> s.head() 0 3/11/2000 1 3/12/2000 2 3/13/2000 3 3/11/2000 4 3/12/2000 dtype: object >>> import timeit >>> timeit.timeit( ... lambda: repr(ps.to_datetime(s, infer_datetime_format=True)), ... number = 1) # doctest: +SKIP 0.35832712500000063 >>> timeit.timeit( ... lambda: repr(ps.to_datetime(s, infer_datetime_format=False)), ... number = 1) # doctest: +SKIP 0.8895321660000004 Using a unix epoch time >>> ps.to_datetime(1490195805, unit='s') Timestamp('2017-03-22 15:16:45') >>> ps.to_datetime(1490195805433502912, unit='ns') Timestamp('2017-03-22 15:16:45.433502912') Using a non-unix epoch origin >>> ps.to_datetime([1, 2, 3], unit='D', origin=pd.Timestamp('1960-01-01')) DatetimeIndex(['1960-01-02', '1960-01-03', '1960-01-04'], dtype='datetime64[ns]', freq=None) """ # mappings for assembling units # From pandas: pandas.core.tools.datetimes _unit_map = { "year": "year", "years": "year", "month": "month", "months": "month", "day": "day", "days": "day", "hour": "h", "hours": "h", "minute": "m", "minutes": "m", "second": "s", "seconds": "s", "ms": "ms", "millisecond": "ms", "milliseconds": "ms", "us": "us", "microsecond": "us", "microseconds": "us", } def pandas_to_datetime( pser_or_pdf: Union[pd.DataFrame, pd.Series], cols: Optional[List[str]] = None ) -> Series[np.datetime64]: if isinstance(pser_or_pdf, pd.DataFrame): pser_or_pdf = pser_or_pdf[cols] return pd.to_datetime( pser_or_pdf, errors=errors, format=format, unit=unit, infer_datetime_format=infer_datetime_format, origin=origin, ) if isinstance(arg, Series): return arg.pandas_on_spark.transform_batch(pandas_to_datetime) if isinstance(arg, DataFrame): unit = {k: _unit_map[k.lower()] for k in arg.keys() if k.lower() in _unit_map} unit_rev = {v: k for k, v in unit.items()} list_cols = [unit_rev["year"], unit_rev["month"], unit_rev["day"]] for u in ["h", "m", "s", "ms", "us"]: value = unit_rev.get(u) if value is not None and value in arg: list_cols.append(value) psdf = arg[list_cols] return psdf.pandas_on_spark.transform_batch(pandas_to_datetime, list_cols) return pd.to_datetime( arg, errors=errors, format=format, unit=unit, infer_datetime_format=infer_datetime_format, origin=origin, )
[docs]def date_range( start: Union[str, Any] = None, end: Union[str, Any] = None, periods: Optional[int] = None, freq: Optional[Union[str, DateOffset]] = None, tz: Optional[Union[str, tzinfo]] = None, normalize: bool = False, name: Optional[str] = None, inclusive: str = "both", **kwargs: Any, ) -> DatetimeIndex: """ Return a fixed frequency DatetimeIndex. Parameters ---------- start : str or datetime-like, optional Left bound for generating dates. end : str or datetime-like, optional Right bound for generating dates. periods : int, optional Number of periods to generate. freq : str or DateOffset, default 'D' Frequency strings can have multiples, e.g. '5H'. tz : str or tzinfo, optional Time zone name for returning localized DatetimeIndex, for example 'Asia/Hong_Kong'. By default, the resulting DatetimeIndex is time zone naive. normalize : bool, default False Normalize start/end dates to midnight before generating date range. name : str, default None Name of the resulting DatetimeIndex. inclusive : {"both", "neither", "left", "right"}, default "both" Include boundaries; Whether to set each bound as closed or open. .. versionadded:: 4.0.0 **kwargs For compatibility. Has no effect on the result. Returns ------- rng : DatetimeIndex See Also -------- DatetimeIndex : An immutable container for datetimes. Notes ----- Of the four parameters ``start``, ``end``, ``periods``, and ``freq``, exactly three must be specified. If ``freq`` is omitted, the resulting ``DatetimeIndex`` will have ``periods`` linearly spaced elements between ``start`` and ``end`` (closed on both sides). To learn more about the frequency strings, please see `this link <https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__. Examples -------- **Specifying the values** The next four examples generate the same `DatetimeIndex`, but vary the combination of `start`, `end` and `periods`. Specify `start` and `end`, with the default daily frequency. >>> ps.date_range(start='1/1/2018', end='1/08/2018') # doctest: +SKIP DatetimeIndex(['2018-01-01', '2018-01-02', '2018-01-03', '2018-01-04', '2018-01-05', '2018-01-06', '2018-01-07', '2018-01-08'], dtype='datetime64[ns]', freq=None) Specify `start` and `periods`, the number of periods (days). >>> ps.date_range(start='1/1/2018', periods=8) # doctest: +SKIP DatetimeIndex(['2018-01-01', '2018-01-02', '2018-01-03', '2018-01-04', '2018-01-05', '2018-01-06', '2018-01-07', '2018-01-08'], dtype='datetime64[ns]', freq=None) Specify `end` and `periods`, the number of periods (days). >>> ps.date_range(end='1/1/2018', periods=8) # doctest: +SKIP DatetimeIndex(['2017-12-25', '2017-12-26', '2017-12-27', '2017-12-28', '2017-12-29', '2017-12-30', '2017-12-31', '2018-01-01'], dtype='datetime64[ns]', freq=None) Specify `start`, `end`, and `periods`; the frequency is generated automatically (linearly spaced). >>> ps.date_range( ... start='2018-04-24', end='2018-04-27', periods=3 ... ) # doctest: +SKIP DatetimeIndex(['2018-04-24 00:00:00', '2018-04-25 12:00:00', '2018-04-27 00:00:00'], dtype='datetime64[ns]', freq=None) **Other Parameters** Changed the `freq` (frequency) to ``'M'`` (month end frequency). >>> ps.date_range(start='1/1/2018', periods=5, freq='M') # doctest: +SKIP DatetimeIndex(['2018-01-31', '2018-02-28', '2018-03-31', '2018-04-30', '2018-05-31'], dtype='datetime64[ns]', freq=None) Multiples are allowed >>> ps.date_range(start='1/1/2018', periods=5, freq='3M') # doctest: +SKIP DatetimeIndex(['2018-01-31', '2018-04-30', '2018-07-31', '2018-10-31', '2019-01-31'], dtype='datetime64[ns]', freq=None) `freq` can also be specified as an Offset object. >>> ps.date_range( ... start='1/1/2018', periods=5, freq=pd.offsets.MonthEnd(3) ... ) # doctest: +SKIP DatetimeIndex(['2018-01-31', '2018-04-30', '2018-07-31', '2018-10-31', '2019-01-31'], dtype='datetime64[ns]', freq=None) `inclusive` controls whether to include `start` and `end` that are on the boundary. The default includes boundary points on either end. >>> ps.date_range( ... start='2017-01-01', end='2017-01-04', inclusive="both" ... ) # doctest: +NORMALIZE_WHITESPACE DatetimeIndex(['2017-01-01', '2017-01-02', '2017-01-03', '2017-01-04'], dtype='datetime64[ns]', freq=None) Use ``inclusive='left'`` to exclude `end` if it falls on the boundary. >>> ps.date_range( ... start='2017-01-01', end='2017-01-04', inclusive='left' ... ) # doctest: +NORMALIZE_WHITESPACE DatetimeIndex(['2017-01-01', '2017-01-02', '2017-01-03'], dtype='datetime64[ns]', freq=None) Use ``inclusive='right'`` to exclude `start` if it falls on the boundary. >>> ps.date_range( ... start='2017-01-01', end='2017-01-04', inclusive='right' ... ) # doctest: +NORMALIZE_WHITESPACE DatetimeIndex(['2017-01-02', '2017-01-03', '2017-01-04'], dtype='datetime64[ns]', freq=None) """ assert freq not in ["N", "ns"], "nanoseconds is not supported" assert tz is None, "Localized DatetimeIndex is not supported" return cast( DatetimeIndex, ps.from_pandas( pd.date_range( start=start, end=end, periods=periods, freq=freq, tz=tz, normalize=normalize, name=name, inclusive=inclusive, **kwargs, ) ), )
[docs]@no_type_check def to_timedelta( arg, unit: Optional[str] = None, errors: str = "raise", ): """ Convert argument to timedelta. Parameters ---------- arg : str, timedelta, list-like or Series The data to be converted to timedelta. unit : str, optional Denotes the unit of the arg for numeric `arg`. Defaults to ``"ns"``. Possible values: * 'W' * 'D' / 'days' / 'day' * 'hours' / 'hour' / 'hr' / 'h' * 'm' / 'minute' / 'min' / 'minutes' / 'T' * 'S' / 'seconds' / 'sec' / 'second' * 'ms' / 'milliseconds' / 'millisecond' / 'milli' / 'millis' / 'L' * 'us' / 'microseconds' / 'microsecond' / 'micro' / 'micros' / 'U' * 'ns' / 'nanoseconds' / 'nano' / 'nanos' / 'nanosecond' / 'N' Must not be specified when `arg` context strings and ``errors="raise"``. .. deprecated:: 4.0.0 Units 'T' and 'L' are deprecated and will be removed in a future version. errors : {'ignore', 'raise', 'coerce'}, default 'raise' - If 'raise', then invalid parsing will raise an exception. - If 'coerce', then invalid parsing will be set as NaT. - If 'ignore', then invalid parsing will return the input. Returns ------- ret : timedelta64, TimedeltaIndex or Series of timedelta64 if parsing succeeded. See Also -------- DataFrame.astype : Cast argument to a specified dtype. to_datetime : Convert argument to datetime. Notes ----- If the precision is higher than nanoseconds, the precision of the duration is truncated to nanoseconds for string inputs. Examples -------- Parsing a single string to a Timedelta: >>> ps.to_timedelta('1 days 06:05:01.00003') Timedelta('1 days 06:05:01.000030') >>> ps.to_timedelta('15.5us') # doctest: +SKIP Timedelta('0 days 00:00:00.000015500') Parsing a list or array of strings: >>> ps.to_timedelta(['1 days 06:05:01.00003', '15.5us', 'nan']) # doctest: +SKIP TimedeltaIndex(['1 days 06:05:01.000030', '0 days 00:00:00.000015500', NaT], dtype='timedelta64[ns]', freq=None) Converting numbers by specifying the `unit` keyword argument: >>> ps.to_timedelta(np.arange(5), unit='s') # doctest: +SKIP TimedeltaIndex(['0 days 00:00:00', '0 days 00:00:01', '0 days 00:00:02', '0 days 00:00:03', '0 days 00:00:04'], dtype='timedelta64[ns]', freq=None) >>> ps.to_timedelta(np.arange(5), unit='d') # doctest: +NORMALIZE_WHITESPACE TimedeltaIndex(['0 days', '1 days', '2 days', '3 days', '4 days'], dtype='timedelta64[ns]', freq=None) """ def pandas_to_timedelta(pser: pd.Series) -> np.timedelta64: return pd.to_timedelta( arg=pser, unit=unit, errors=errors, ) if isinstance(arg, Series): return arg.transform(pandas_to_timedelta) else: return pd.to_timedelta( arg=arg, unit=unit, errors=errors, )
[docs]def timedelta_range( start: Union[str, Any] = None, end: Union[str, Any] = None, periods: Optional[int] = None, freq: Optional[Union[str, DateOffset]] = None, name: Optional[str] = None, closed: Optional[str] = None, ) -> TimedeltaIndex: """ Return a fixed frequency TimedeltaIndex, with day as the default frequency. Parameters ---------- start : str or timedelta-like, optional Left bound for generating timedeltas. end : str or timedelta-like, optional Right bound for generating timedeltas. periods : int, optional Number of periods to generate. freq : str or DateOffset, default 'D' Frequency strings can have multiples, e.g. '5H'. name : str, default None Name of the resulting TimedeltaIndex. closed : {None, 'left', 'right'}, optional Make the interval closed with respect to the given frequency to the 'left', 'right', or both sides (None, the default). Returns ------- TimedeltaIndex Notes ----- Of the four parameters ``start``, ``end``, ``periods``, and ``freq``, exactly three must be specified. If ``freq`` is omitted, the resulting ``TimedeltaIndex`` will have ``periods`` linearly spaced elements between ``start`` and ``end`` (closed on both sides). To learn more about the frequency strings, please see `this link <https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__. Examples -------- >>> ps.timedelta_range(start='1 day', periods=4) # doctest: +NORMALIZE_WHITESPACE TimedeltaIndex(['1 days', '2 days', '3 days', '4 days'], dtype='timedelta64[ns]', freq=None) The closed parameter specifies which endpoint is included. The default behavior is to include both endpoints. >>> ps.timedelta_range(start='1 day', periods=4, closed='right') ... # doctest: +NORMALIZE_WHITESPACE TimedeltaIndex(['2 days', '3 days', '4 days'], dtype='timedelta64[ns]', freq=None) The freq parameter specifies the frequency of the TimedeltaIndex. Only fixed frequencies can be passed, non-fixed frequencies such as ‘M’ (month end) will raise. >>> ps.timedelta_range(start='1 day', end='2 days', freq='6H') ... # doctest: +NORMALIZE_WHITESPACE TimedeltaIndex(['1 days 00:00:00', '1 days 06:00:00', '1 days 12:00:00', '1 days 18:00:00', '2 days 00:00:00'], dtype='timedelta64[ns]', freq=None) Specify start, end, and periods; the frequency is generated automatically (linearly spaced). >>> ps.timedelta_range(start='1 day', end='5 days', periods=4) ... # doctest: +NORMALIZE_WHITESPACE TimedeltaIndex(['1 days 00:00:00', '2 days 08:00:00', '3 days 16:00:00', '5 days 00:00:00'], dtype='timedelta64[ns]', freq=None) """ assert freq not in ["N", "ns"], "nanoseconds is not supported" return cast( TimedeltaIndex, ps.from_pandas( pd.timedelta_range( start=start, end=end, periods=periods, freq=freq, name=name, closed=closed, ) ), )
[docs]def get_dummies( data: Union[DataFrame, Series], prefix: Optional[Union[str, List[str], Dict[str, str]]] = None, prefix_sep: str = "_", dummy_na: bool = False, columns: Optional[Union[Name, List[Name]]] = None, sparse: bool = False, drop_first: bool = False, dtype: Optional[Union[str, Dtype]] = None, ) -> DataFrame: """ Convert categorical variable into dummy/indicator variables, also known as one hot encoding. Parameters ---------- data : array-like, Series, or DataFrame prefix : string, list of strings, or dict of strings, default None String to append DataFrame column names. Pass a list with length equal to the number of columns when calling get_dummies on a DataFrame. Alternatively, `prefix` can be a dictionary mapping column names to prefixes. prefix_sep : string, default '_' If appending prefix, separator/delimiter to use. Or pass a list or dictionary as with `prefix.` dummy_na : bool, default False Add a column to indicate NaNs, if False NaNs are ignored. columns : list-like, default None Column names in the DataFrame to be encoded. If `columns` is None then all the columns with `object` or `category` dtype will be converted. sparse : bool, default False Whether the dummy-encoded columns should be be backed by a :class:`SparseArray` (True) or a regular NumPy array (False). In pandas-on-Spark, this value must be "False". drop_first : bool, default False Whether to get k-1 dummies out of k categorical levels by removing the first level. dtype : dtype, default np.uint8 Data type for new columns. Only a single dtype is allowed. Returns ------- dummies : DataFrame See Also -------- Series.str.get_dummies Examples -------- >>> s = ps.Series(list('abca')) >>> ps.get_dummies(s) a b c 0 1 0 0 1 0 1 0 2 0 0 1 3 1 0 0 >>> df = ps.DataFrame({'A': ['a', 'b', 'a'], 'B': ['b', 'a', 'c'], ... 'C': [1, 2, 3]}, ... columns=['A', 'B', 'C']) >>> ps.get_dummies(df, prefix=['col1', 'col2']) C col1_a col1_b col2_a col2_b col2_c 0 1 1 0 0 1 0 1 2 0 1 1 0 0 2 3 1 0 0 0 1 >>> ps.get_dummies(ps.Series(list('abcaa'))) a b c 0 1 0 0 1 0 1 0 2 0 0 1 3 1 0 0 4 1 0 0 >>> ps.get_dummies(ps.Series(list('abcaa')), drop_first=True) b c 0 0 0 1 1 0 2 0 1 3 0 0 4 0 0 >>> ps.get_dummies(ps.Series(list('abc')), dtype=float) a b c 0 1.0 0.0 0.0 1 0.0 1.0 0.0 2 0.0 0.0 1.0 """ if sparse is not False: raise NotImplementedError("get_dummies currently does not support sparse") if columns is not None and not is_list_like(columns): raise TypeError("Input must be a list-like for parameter `columns`") if dtype is None: dtype = "byte" if isinstance(data, Series): if prefix is not None: prefix = [str(prefix)] psdf = data.to_frame() column_labels = psdf._internal.column_labels remaining_columns = [] else: if isinstance(prefix, str): raise NotImplementedError( "get_dummies currently does not support prefix as string types" ) psdf = data.copy() if columns is None: column_labels = [ label for label in psdf._internal.column_labels if isinstance( psdf._internal.spark_type_for(label), _get_dummies_default_accept_types ) ] else: if is_name_like_tuple(columns): column_labels = [ label for label in psdf._internal.column_labels if label[: len(columns)] == columns ] if len(column_labels) == 0: raise KeyError(name_like_string(columns)) if prefix is None: prefix = [ str(label[len(columns) :]) if len(label) > len(columns) + 1 else label[len(columns)] if len(label) == len(columns) + 1 else "" for label in column_labels ] elif any(isinstance(col, tuple) for col in columns) and any( not is_name_like_tuple(col) for col in columns ): raise ValueError( "Expected tuple, got {}".format( type(set(col for col in columns if not is_name_like_tuple(col)).pop()) ) ) else: column_labels = [ label for key in columns for label in psdf._internal.column_labels if label == key or label[0] == key ] if len(column_labels) == 0: if columns is None: return psdf raise KeyError("{} not in index".format(columns)) if prefix is None: prefix = [str(label) if len(label) > 1 else label[0] for label in column_labels] column_labels_set = set(column_labels) remaining_columns = [ ( psdf[label] if psdf._internal.column_labels_level == 1 else psdf[label].rename(name_like_string(label)) ) for label in psdf._internal.column_labels if label not in column_labels_set ] if any( not isinstance(psdf._internal.spark_type_for(label), _get_dummies_acceptable_types) for label in column_labels ): raise NotImplementedError( "get_dummies currently only accept {} values".format( ", ".join( [cast(Type[DataType], t).typeName() for t in _get_dummies_acceptable_types] ) ) ) if prefix is not None and len(column_labels) != len(prefix): raise ValueError( "Length of 'prefix' ({}) did not match the length of " "the columns being encoded ({}).".format(len(prefix), len(column_labels)) ) elif isinstance(prefix, dict): prefix = [prefix[column_label[0]] for column_label in column_labels] all_values = _reduce_spark_multi( psdf._internal.spark_frame, [F.collect_set(psdf._internal.spark_column_for(label)) for label in column_labels], ) for i, label in enumerate(column_labels): values = all_values[i] if isinstance(values, np.ndarray): values = values.tolist() values = sorted(values) if drop_first: values = values[1:] def column_name(v: Any) -> Name: if prefix is None or prefix[i] == "": # type: ignore[index] return v else: return "{}{}{}".format(prefix[i], prefix_sep, v) # type: ignore[index] for value in values: remaining_columns.append( (psdf[label].notnull() & (psdf[label] == value)) .astype(dtype) .rename(column_name(value)) ) if dummy_na: remaining_columns.append(psdf[label].isnull().astype(dtype).rename(column_name(np.nan))) return psdf[remaining_columns]
# TODO: there are many parameters to implement and support. See pandas's pd.concat.
[docs]def concat( objs: List[Union[DataFrame, Series]], axis: Axis = 0, join: str = "outer", ignore_index: bool = False, sort: bool = False, ) -> Union[Series, DataFrame]: """ Concatenate pandas-on-Spark objects along a particular axis with optional set logic along the other axes. Parameters ---------- objs : a sequence of Series or DataFrame Any None objects will be dropped silently unless they are all None in which case a ValueError will be raised axis : {0/'index', 1/'columns'}, default 0 The axis to concatenate along. join : {'inner', 'outer'}, default 'outer' How to handle indexes on other axis (or axes). ignore_index : bool, default False If True, do not use the index values along the concatenation axis. The resulting axis will be labeled 0, ..., n - 1. This is useful if you are concatenating objects where the concatenation axis does not have meaningful indexing information. Note the index values on the other axes are still respected in the join. sort : bool, default False Sort non-concatenation axis if it is not already aligned. Returns ------- object, type of objs When concatenating all ``Series`` along the index (axis=0), a ``Series`` is returned. When ``objs`` contains at least one ``DataFrame``, a ``DataFrame`` is returned. When concatenating along the columns (axis=1), a ``DataFrame`` is returned. See Also -------- DataFrame.join : Join DataFrames using indexes. DataFrame.merge : Merge DataFrames by indexes or columns. Examples -------- >>> from pyspark.pandas.config import set_option, reset_option >>> set_option("compute.ops_on_diff_frames", True) Combine two ``Series``. >>> s1 = ps.Series(['a', 'b']) >>> s2 = ps.Series(['c', 'd']) >>> ps.concat([s1, s2]) 0 a 1 b 0 c 1 d dtype: object Clear the existing index and reset it in the result by setting the ``ignore_index`` option to ``True``. >>> ps.concat([s1, s2], ignore_index=True) 0 a 1 b 2 c 3 d dtype: object Combine two ``DataFrame`` objects with identical columns. >>> df1 = ps.DataFrame([['a', 1], ['b', 2]], ... columns=['letter', 'number']) >>> df1 letter number 0 a 1 1 b 2 >>> df2 = ps.DataFrame([['c', 3], ['d', 4]], ... columns=['letter', 'number']) >>> df2 letter number 0 c 3 1 d 4 >>> ps.concat([df1, df2]) letter number 0 a 1 1 b 2 0 c 3 1 d 4 Combine ``DataFrame`` and ``Series`` objects with different columns. >>> ps.concat([df2, s1]) letter number 0 0 c 3.0 None 1 d 4.0 None 0 None NaN a 1 None NaN b Combine ``DataFrame`` objects with overlapping columns and return everything. Columns outside the intersection will be filled with ``None`` values. >>> df3 = ps.DataFrame([['c', 3, 'cat'], ['d', 4, 'dog']], ... columns=['letter', 'number', 'animal']) >>> df3 letter number animal 0 c 3 cat 1 d 4 dog >>> ps.concat([df1, df3]) letter number animal 0 a 1 None 1 b 2 None 0 c 3 cat 1 d 4 dog Sort the columns. >>> ps.concat([df1, df3], sort=True) animal letter number 0 None a 1 1 None b 2 0 cat c 3 1 dog d 4 Combine ``DataFrame`` objects with overlapping columns and return only those that are shared by passing ``inner`` to the ``join`` keyword argument. >>> ps.concat([df1, df3], join="inner") letter number 0 a 1 1 b 2 0 c 3 1 d 4 >>> df4 = ps.DataFrame([['bird', 'polly'], ['monkey', 'george']], ... columns=['animal', 'name']) Combine with column axis. >>> ps.concat([df1, df4], axis=1) letter number animal name 0 a 1 bird polly 1 b 2 monkey george >>> reset_option("compute.ops_on_diff_frames") """ if isinstance(objs, (DataFrame, IndexOpsMixin)) or not isinstance( objs, Iterable ): # TODO: support dict raise TypeError( "first argument must be an iterable of pandas-on-Spark " "objects, you passed an object of type " '"{name}"'.format(name=type(objs).__name__) ) if len(cast(Sized, objs)) == 0: raise ValueError("No objects to concatenate") objs = list(filter(lambda obj: obj is not None, objs)) if len(objs) == 0: raise ValueError("All objects passed were None") for obj in objs: if not isinstance(obj, (Series, DataFrame)): raise TypeError( "cannot concatenate object of type " "'{name}" "; only ps.Series " "and ps.DataFrame are valid".format(name=type(objs).__name__) ) if join not in ["inner", "outer"]: raise ValueError("Only can inner (intersect) or outer (union) join the other axis.") if all([obj.empty for obj in objs]): warnings.warn( "The behavior of array concatenation with empty entries is " "deprecated. In a future version, this will no longer exclude " "empty items when determining the result dtype. " "To retain the old behavior, exclude the empty entries before " "the concat operation.", FutureWarning, ) axis = validate_axis(axis) psdf: DataFrame if axis == 1: psdfs: List[DataFrame] = [ obj.to_frame() if isinstance(obj, Series) else obj for obj in objs ] level: int = min(psdf._internal.column_labels_level for psdf in psdfs) psdfs = [ DataFrame._index_normalized_frame(level, psdf) if psdf._internal.column_labels_level > level else psdf for psdf in psdfs ] concat_psdf = psdfs[0] column_labels: List[Label] = concat_psdf._internal.column_labels.copy() psdfs_not_same_anchor = [] for psdf in psdfs[1:]: duplicated = [label for label in psdf._internal.column_labels if label in column_labels] if len(duplicated) > 0: pretty_names = [name_like_string(label) for label in duplicated] raise ValueError( "Labels have to be unique; however, got duplicated labels %s." % pretty_names ) column_labels.extend(psdf._internal.column_labels) if same_anchor(concat_psdf, psdf): concat_psdf = DataFrame( concat_psdf._internal.with_new_columns( [ concat_psdf._psser_for(label) for label in concat_psdf._internal.column_labels ] + [psdf._psser_for(label) for label in psdf._internal.column_labels] ) ) else: psdfs_not_same_anchor.append(psdf) if len(psdfs_not_same_anchor) > 0: @no_type_check def resolve_func(psdf, this_column_labels, that_column_labels): raise AssertionError("This should not happen.") for psdf in psdfs_not_same_anchor: if join == "inner": concat_psdf = align_diff_frames( resolve_func, concat_psdf, psdf, fillna=False, how="inner", ) elif join == "outer": concat_psdf = align_diff_frames( resolve_func, concat_psdf, psdf, fillna=False, how="full", ) concat_psdf = concat_psdf[column_labels] if ignore_index: concat_psdf.columns = list( # type: ignore[assignment] map(str, _range(len(concat_psdf.columns))) ) if sort: concat_psdf = concat_psdf.sort_index() columns = concat_psdf.columns if isinstance(columns, pd.MultiIndex): concat_psdf = concat_psdf.rename_axis([None] * columns.nlevels, axis="columns") return concat_psdf # Series, Series ... # We should return Series if objects are all Series. should_return_series = all(map(lambda obj: isinstance(obj, Series), objs)) # DataFrame, Series ... & Series, Series ... # In this case, we should return DataFrame. new_objs: List[DataFrame] = [] num_series = 0 series_names = set() for obj in objs: if isinstance(obj, Series): num_series += 1 series_names.add(obj.name) if not ignore_index and not should_return_series: new_objs.append(obj.to_frame()) else: new_objs.append(obj.to_frame(DEFAULT_SERIES_NAME)) else: assert isinstance(obj, DataFrame) new_objs.append(obj) column_labels_levels: Set[int] = set(obj._internal.column_labels_level for obj in new_objs) if len(column_labels_levels) != 1: raise ValueError("MultiIndex columns should have the same levels") # DataFrame, DataFrame, ... # All Series are converted into DataFrame and then compute concat. if not ignore_index: indices_of_psdfs = [psdf.index for psdf in new_objs] index_of_first_psdf = indices_of_psdfs[0] for index_of_psdf in indices_of_psdfs: if index_of_first_psdf.names != index_of_psdf.names: raise ValueError( "Index type and names should be same in the objects to concatenate. " "You passed different indices " "{index_of_first_psdf} and {index_of_psdf}".format( index_of_first_psdf=index_of_first_psdf.names, index_of_psdf=index_of_psdf.names, ) ) column_labels_of_psdfs = [psdf._internal.column_labels for psdf in new_objs] index_names_of_psdfs: List[List[Optional[Label]]] if ignore_index: index_names_of_psdfs = [[] for _ in new_objs] else: index_names_of_psdfs = [psdf._internal.index_names for psdf in new_objs] if all(name == index_names_of_psdfs[0] for name in index_names_of_psdfs) and all( idx == column_labels_of_psdfs[0] for idx in column_labels_of_psdfs ): # If all columns are in the same order and values, use it. psdfs = new_objs else: if join == "inner": interested_columns = set.intersection(*map(lambda x: set(x), column_labels_of_psdfs)) # Keep the column order with its firsts DataFrame. merged_columns = [ label for label in column_labels_of_psdfs[0] if label in interested_columns ] # If sort is True, sort to follow pandas 1.4+ behavior. if sort: # FIXME: better ordering merged_columns = sorted(merged_columns, key=name_like_string) psdfs = [psdf[merged_columns] for psdf in new_objs] elif join == "outer": merged_columns = [] for labels in column_labels_of_psdfs: merged_columns.extend(label for label in labels if label not in merged_columns) assert len(merged_columns) > 0 # If sort is True, always sort if sort: # FIXME: better ordering merged_columns = sorted(merged_columns, key=name_like_string) psdfs = [] for psdf in new_objs: columns_to_add = list(set(merged_columns) - set(psdf._internal.column_labels)) # TODO: NaN and None difference for missing values. pandas seems to be filling NaN. sdf = psdf._internal.resolved_copy.spark_frame for label in columns_to_add: sdf = sdf.withColumn(name_like_string(label), F.lit(None)) data_columns = psdf._internal.data_spark_column_names + [ name_like_string(label) for label in columns_to_add ] psdf = DataFrame( psdf._internal.copy( spark_frame=sdf, index_spark_columns=[ scol_for(sdf, col) for col in psdf._internal.index_spark_column_names ], column_labels=(psdf._internal.column_labels + columns_to_add), data_spark_columns=[scol_for(sdf, col) for col in data_columns], data_fields=(psdf._internal.data_fields + ([None] * len(columns_to_add))), ) ) psdfs.append(psdf[merged_columns]) if ignore_index: sdfs = [ psdf._internal.spark_frame.select(psdf._internal.data_spark_columns) for psdf in psdfs ] else: sdfs = [ psdf._internal.spark_frame.select( psdf._internal.index_spark_columns + psdf._internal.data_spark_columns ) for psdf in psdfs ] concatenated = reduce(lambda x, y: x.union(y), sdfs) if ignore_index: index_spark_column_names = [] index_names = [] index_fields = [] else: index_spark_column_names = psdfs[0]._internal.index_spark_column_names index_names = psdfs[0]._internal.index_names index_fields = psdfs[0]._internal.index_fields result_psdf: DataFrame = DataFrame( psdfs[0]._internal.copy( spark_frame=concatenated, index_spark_columns=[scol_for(concatenated, col) for col in index_spark_column_names], index_names=index_names, index_fields=index_fields, data_spark_columns=[ scol_for(concatenated, col) for col in psdfs[0]._internal.data_spark_column_names ], data_fields=None, # TODO: dtypes? ) ) if should_return_series: # If all input were Series, we should return Series. if len(series_names) == 1: name = series_names.pop() else: name = None return first_series(result_psdf).rename(name) else: return result_psdf
[docs]def melt( frame: DataFrame, id_vars: Optional[Union[Name, List[Name]]] = None, value_vars: Optional[Union[Name, List[Name]]] = None, var_name: Optional[Union[str, List[str]]] = None, value_name: str = "value", ) -> DataFrame: return DataFrame.melt(frame, id_vars, value_vars, var_name, value_name)
melt.__doc__ = DataFrame.melt.__doc__
[docs]@no_type_check def isna(obj): """ Detect missing values for an array-like object. This function takes a scalar or array-like object and indicates whether values are missing (``NaN`` in numeric arrays, ``None`` or ``NaN`` in object arrays). Parameters ---------- obj : scalar or array-like Object to check for null or missing values. Returns ------- bool or array-like of bool For scalar input, returns a scalar boolean. For array input, returns an array of boolean indicating whether each corresponding element is missing. See Also -------- Series.isna : Detect missing values in a Series. Series.isnull : Detect missing values in a Series. DataFrame.isna : Detect missing values in a DataFrame. DataFrame.isnull : Detect missing values in a DataFrame. Index.isna : Detect missing values in an Index. Index.isnull : Detect missing values in an Index. Examples -------- Scalar arguments (including strings) result in a scalar boolean. >>> ps.isna('dog') False >>> ps.isna(np.nan) True ndarrays result in an ndarray of booleans. >>> array = np.array([[1, np.nan, 3], [4, 5, np.nan]]) >>> array array([[ 1., nan, 3.], [ 4., 5., nan]]) >>> ps.isna(array) array([[False, True, False], [False, False, True]]) For Series and DataFrame, the same type is returned, containing booleans. >>> df = ps.DataFrame({'a': ['ant', 'bee', 'cat'], 'b': ['dog', None, 'fly']}) >>> df a b 0 ant dog 1 bee None 2 cat fly >>> ps.isna(df) a b 0 False False 1 False True 2 False False >>> ps.isnull(df.b) 0 False 1 True 2 False Name: b, dtype: bool """ # TODO: Add back: # notnull : Boolean inverse of pandas.isnull. # into the See Also in the docstring. It does not find the method in the latest numpydoc. if isinstance(obj, (DataFrame, Series)): return obj.isnull() else: return pd.isnull(obj)
isnull = isna
[docs]@no_type_check def notna(obj): """ Detect existing (non-missing) values. Return a boolean same-sized object indicating if the values are not NA. Non-missing values get mapped to True. NA values, such as None or :attr:`numpy.NaN`, get mapped to False values. Returns ------- bool or array-like of bool Mask of bool values for each element that indicates whether an element is not an NA value. See Also -------- isna : Detect missing values for an array-like object. Series.notna : Boolean inverse of Series.isna. DataFrame.notnull : Boolean inverse of DataFrame.isnull. Index.notna : Boolean inverse of Index.isna. Index.notnull : Boolean inverse of Index.isnull. Examples -------- Show which entries in a DataFrame are not NA. >>> df = ps.DataFrame({'age': [5, 6, np.NaN], ... 'born': [pd.NaT, pd.Timestamp('1939-05-27'), ... pd.Timestamp('1940-04-25')], ... 'name': ['Alfred', 'Batman', ''], ... 'toy': [None, 'Batmobile', 'Joker']}) >>> df age born name toy 0 5.0 NaT Alfred None 1 6.0 1939-05-27 Batman Batmobile 2 NaN 1940-04-25 Joker >>> df.notnull() age born name toy 0 True False True False 1 True True True True 2 False True True True Show which entries in a Series are not NA. >>> ser = ps.Series([5, 6, np.NaN]) >>> ser 0 5.0 1 6.0 2 NaN dtype: float64 >>> ps.notna(ser) 0 True 1 True 2 False dtype: bool >>> ps.notna(ser.index) True """ # TODO: Add back: # Series.notnull :Boolean inverse of Series.isnull. # DataFrame.notna :Boolean inverse of DataFrame.isna. # into the See Also in the docstring. It does not find the method in the latest numpydoc. if isinstance(obj, (DataFrame, Series)): return obj.notna() else: return pd.notna(obj)
notnull = notna
[docs]def merge( obj: DataFrame, right: DataFrame, how: str = "inner", on: Optional[Union[Name, List[Name]]] = None, left_on: Optional[Union[Name, List[Name]]] = None, right_on: Optional[Union[Name, List[Name]]] = None, left_index: bool = False, right_index: bool = False, suffixes: Tuple[str, str] = ("_x", "_y"), ) -> "DataFrame": """ Merge DataFrame objects with a database-style join. The index of the resulting DataFrame will be one of the following: - 0...n if no index is used for merging - Index of the left DataFrame if merged only on the index of the right DataFrame - Index of the right DataFrame if merged only on the index of the left DataFrame - All involved indices if merged using the indices of both DataFrames e.g. if `left` with indices (a, x) and `right` with indices (b, x), the result will be an index (x, a, b) Parameters ---------- right: Object to merge with. how: Type of merge to be performed. {'left', 'right', 'outer', 'inner'}, default 'inner' left: use only keys from left frame, like a SQL left outer join; preserve key order. right: use only keys from right frame, like a SQL right outer join; preserve key order. outer: use union of keys from both frames, like a SQL full outer join; sort keys lexicographically. inner: use intersection of keys from both frames, like a SQL inner join; preserve the order of the left keys. on: Column or index level names to join on. These must be found in both DataFrames. If on is None and not merging on indexes then this defaults to the intersection of the columns in both DataFrames. left_on: Column or index level names to join on in the left DataFrame. Can also be an array or list of arrays of the length of the left DataFrame. These arrays are treated as if they are columns. right_on: Column or index level names to join on in the right DataFrame. Can also be an array or list of arrays of the length of the right DataFrame. These arrays are treated as if they are columns. left_index: Use the index from the left DataFrame as the join key(s). If it is a MultiIndex, the number of keys in the other DataFrame (either the index or a number of columns) must match the number of levels. right_index: Use the index from the right DataFrame as the join key. Same caveats as left_index. suffixes: Suffix to apply to overlapping column names in the left and right side, respectively. Returns ------- DataFrame A DataFrame of the two merged objects. Examples -------- >>> df1 = ps.DataFrame({'lkey': ['foo', 'bar', 'baz', 'foo'], ... 'value': [1, 2, 3, 5]}, ... columns=['lkey', 'value']) >>> df2 = ps.DataFrame({'rkey': ['foo', 'bar', 'baz', 'foo'], ... 'value': [5, 6, 7, 8]}, ... columns=['rkey', 'value']) >>> df1 lkey value 0 foo 1 1 bar 2 2 baz 3 3 foo 5 >>> df2 rkey value 0 foo 5 1 bar 6 2 baz 7 3 foo 8 Merge df1 and df2 on the lkey and rkey columns. The value columns have the default suffixes, _x and _y, appended. >>> merged = ps.merge(df1, df2, left_on='lkey', right_on='rkey') >>> merged.sort_values(by=['lkey', 'value_x', 'rkey', 'value_y']) # doctest: +ELLIPSIS lkey value_x rkey value_y ...bar 2 bar 6 ...baz 3 baz 7 ...foo 1 foo 5 ...foo 1 foo 8 ...foo 5 foo 5 ...foo 5 foo 8 >>> left_psdf = ps.DataFrame({'A': [1, 2]}) >>> right_psdf = ps.DataFrame({'B': ['x', 'y']}, index=[1, 2]) >>> ps.merge(left_psdf, right_psdf, left_index=True, right_index=True).sort_index() A B 1 2 x >>> ps.merge(left_psdf, right_psdf, left_index=True, right_index=True, how='left').sort_index() A B 0 1 None 1 2 x >>> ps.merge(left_psdf, right_psdf, left_index=True, right_index=True, how='right').sort_index() A B 1 2.0 x 2 NaN y >>> ps.merge(left_psdf, right_psdf, left_index=True, right_index=True, how='outer').sort_index() A B 0 1.0 None 1 2.0 x 2 NaN y Notes ----- As described in #263, joining string columns currently returns None for missing values instead of NaN. """ return obj.merge( right, how=how, on=on, left_on=left_on, right_on=right_on, left_index=left_index, right_index=right_index, suffixes=suffixes, )
[docs]def merge_asof( left: Union[DataFrame, Series], right: Union[DataFrame, Series], on: Optional[Name] = None, left_on: Optional[Name] = None, right_on: Optional[Name] = None, left_index: bool = False, right_index: bool = False, by: Optional[Union[Name, List[Name]]] = None, left_by: Optional[Union[Name, List[Name]]] = None, right_by: Optional[Union[Name, List[Name]]] = None, suffixes: Tuple[str, str] = ("_x", "_y"), tolerance: Optional[Any] = None, allow_exact_matches: bool = True, direction: str = "backward", ) -> DataFrame: """ Perform an asof merge. This is like a left-join except that we match on nearest key rather than equal keys. For each row in the left DataFrame: - A "backward" search selects the last row in the right DataFrame whose 'on' key is less than or equal to the left's key. - A "forward" search selects the first row in the right DataFrame whose 'on' key is greater than or equal to the left's key. - A "nearest" search selects the row in the right DataFrame who's 'on' key is closest in absolute distance to the left's key. Optionally match on equivalent keys with 'by' before searching with 'on'. .. versionadded:: 3.3.0 Parameters ---------- left : DataFrame or named Series right : DataFrame or named Series on : label Field name to join on. Must be found in both DataFrames. The data MUST be ordered. This must be a numeric column, such as datetimelike, integer, or float. On or left_on/right_on must be given. left_on : label Field name to join on in left DataFrame. right_on : label Field name to join on in right DataFrame. left_index : bool Use the index of the left DataFrame as the join key. right_index : bool Use the index of the right DataFrame as the join key. by : column name or list of column names Match on these columns before performing merge operation. left_by : column name Field names to match on in the left DataFrame. right_by : column name Field names to match on in the right DataFrame. suffixes : 2-length sequence (tuple, list, ...) Suffix to apply to overlapping column names in the left and right side, respectively. tolerance : int or Timedelta, optional, default None Select asof tolerance within this range; must be compatible with the merge index. allow_exact_matches : bool, default True - If True, allow matching with the same 'on' value (i.e. less-than-or-equal-to / greater-than-or-equal-to) - If False, don't match the same 'on' value (i.e., strictly less-than / strictly greater-than). direction : 'backward' (default), 'forward', or 'nearest' Whether to search for prior, subsequent, or closest matches. Returns ------- merged : DataFrame See Also -------- merge : Merge with a database-style join. merge_ordered : Merge with optional filling/interpolation. Examples -------- >>> left = ps.DataFrame({"a": [1, 5, 10], "left_val": ["a", "b", "c"]}) >>> left a left_val 0 1 a 1 5 b 2 10 c >>> right = ps.DataFrame({"a": [1, 2, 3, 6, 7], "right_val": [1, 2, 3, 6, 7]}) >>> right a right_val 0 1 1 1 2 2 2 3 3 3 6 6 4 7 7 >>> ps.merge_asof(left, right, on="a").sort_values("a").reset_index(drop=True) a left_val right_val 0 1 a 1 1 5 b 3 2 10 c 7 >>> ps.merge_asof( ... left, ... right, ... on="a", ... allow_exact_matches=False ... ).sort_values("a").reset_index(drop=True) a left_val right_val 0 1 a NaN 1 5 b 3.0 2 10 c 7.0 >>> ps.merge_asof( ... left, ... right, ... on="a", ... direction="forward" ... ).sort_values("a").reset_index(drop=True) a left_val right_val 0 1 a 1.0 1 5 b 6.0 2 10 c NaN >>> ps.merge_asof( ... left, ... right, ... on="a", ... direction="nearest" ... ).sort_values("a").reset_index(drop=True) a left_val right_val 0 1 a 1 1 5 b 6 2 10 c 7 We can use indexed DataFrames as well. >>> left = ps.DataFrame({"left_val": ["a", "b", "c"]}, index=[1, 5, 10]) >>> left left_val 1 a 5 b 10 c >>> right = ps.DataFrame({"right_val": [1, 2, 3, 6, 7]}, index=[1, 2, 3, 6, 7]) >>> right right_val 1 1 2 2 3 3 6 6 7 7 >>> ps.merge_asof(left, right, left_index=True, right_index=True).sort_index() left_val right_val 1 a 1 5 b 3 10 c 7 Here is a real-world times-series example >>> quotes = ps.DataFrame( ... { ... "time": [ ... pd.Timestamp("2016-05-25 13:30:00.023"), ... pd.Timestamp("2016-05-25 13:30:00.023"), ... pd.Timestamp("2016-05-25 13:30:00.030"), ... pd.Timestamp("2016-05-25 13:30:00.041"), ... pd.Timestamp("2016-05-25 13:30:00.048"), ... pd.Timestamp("2016-05-25 13:30:00.049"), ... pd.Timestamp("2016-05-25 13:30:00.072"), ... pd.Timestamp("2016-05-25 13:30:00.075") ... ], ... "ticker": [ ... "GOOG", ... "MSFT", ... "MSFT", ... "MSFT", ... "GOOG", ... "AAPL", ... "GOOG", ... "MSFT" ... ], ... "bid": [720.50, 51.95, 51.97, 51.99, 720.50, 97.99, 720.50, 52.01], ... "ask": [720.93, 51.96, 51.98, 52.00, 720.93, 98.01, 720.88, 52.03] ... } ... ) >>> quotes time ticker bid ask 0 2016-05-25 13:30:00.023 GOOG 720.50 720.93 1 2016-05-25 13:30:00.023 MSFT 51.95 51.96 2 2016-05-25 13:30:00.030 MSFT 51.97 51.98 3 2016-05-25 13:30:00.041 MSFT 51.99 52.00 4 2016-05-25 13:30:00.048 GOOG 720.50 720.93 5 2016-05-25 13:30:00.049 AAPL 97.99 98.01 6 2016-05-25 13:30:00.072 GOOG 720.50 720.88 7 2016-05-25 13:30:00.075 MSFT 52.01 52.03 >>> trades = ps.DataFrame( ... { ... "time": [ ... pd.Timestamp("2016-05-25 13:30:00.023"), ... pd.Timestamp("2016-05-25 13:30:00.038"), ... pd.Timestamp("2016-05-25 13:30:00.048"), ... pd.Timestamp("2016-05-25 13:30:00.048"), ... pd.Timestamp("2016-05-25 13:30:00.048") ... ], ... "ticker": ["MSFT", "MSFT", "GOOG", "GOOG", "AAPL"], ... "price": [51.95, 51.95, 720.77, 720.92, 98.0], ... "quantity": [75, 155, 100, 100, 100] ... } ... ) >>> trades time ticker price quantity 0 2016-05-25 13:30:00.023 MSFT 51.95 75 1 2016-05-25 13:30:00.038 MSFT 51.95 155 2 2016-05-25 13:30:00.048 GOOG 720.77 100 3 2016-05-25 13:30:00.048 GOOG 720.92 100 4 2016-05-25 13:30:00.048 AAPL 98.00 100 By default we are taking the asof of the quotes >>> ps.merge_asof( ... trades, quotes, on="time", by="ticker" ... ).sort_values(["time", "ticker", "price"]).reset_index(drop=True) time ticker price quantity bid ask 0 2016-05-25 13:30:00.023 MSFT 51.95 75 51.95 51.96 1 2016-05-25 13:30:00.038 MSFT 51.95 155 51.97 51.98 2 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN 3 2016-05-25 13:30:00.048 GOOG 720.77 100 720.50 720.93 4 2016-05-25 13:30:00.048 GOOG 720.92 100 720.50 720.93 We only asof within 2ms between the quote time and the trade time >>> ps.merge_asof( ... trades, ... quotes, ... on="time", ... by="ticker", ... tolerance=sf.expr("INTERVAL 2 MILLISECONDS") # pd.Timedelta("2ms") ... ).sort_values(["time", "ticker", "price"]).reset_index(drop=True) time ticker price quantity bid ask 0 2016-05-25 13:30:00.023 MSFT 51.95 75 51.95 51.96 1 2016-05-25 13:30:00.038 MSFT 51.95 155 NaN NaN 2 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN 3 2016-05-25 13:30:00.048 GOOG 720.77 100 720.50 720.93 4 2016-05-25 13:30:00.048 GOOG 720.92 100 720.50 720.93 We only asof within 10ms between the quote time and the trade time and we exclude exact matches on time. However *prior* data will propagate forward >>> ps.merge_asof( ... trades, ... quotes, ... on="time", ... by="ticker", ... tolerance=sf.expr("INTERVAL 10 MILLISECONDS"), # pd.Timedelta("10ms") ... allow_exact_matches=False ... ).sort_values(["time", "ticker", "price"]).reset_index(drop=True) time ticker price quantity bid ask 0 2016-05-25 13:30:00.023 MSFT 51.95 75 NaN NaN 1 2016-05-25 13:30:00.038 MSFT 51.95 155 51.97 51.98 2 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN 3 2016-05-25 13:30:00.048 GOOG 720.77 100 NaN NaN 4 2016-05-25 13:30:00.048 GOOG 720.92 100 NaN NaN """ def to_list(os: Optional[Union[Name, List[Name]]]) -> List[Label]: if os is None: return [] elif is_name_like_tuple(os): return [cast(Label, os)] elif is_name_like_value(os): return [(os,)] else: return [o if is_name_like_tuple(o) else (o,) for o in os] if isinstance(left, Series): left = left.to_frame() if isinstance(right, Series): right = right.to_frame() if on: if left_on or right_on: raise ValueError( 'Can only pass argument "on" OR "left_on" and "right_on", ' "not a combination of both." ) left_as_of_names = list(map(left._internal.spark_column_name_for, to_list(on))) right_as_of_names = list(map(right._internal.spark_column_name_for, to_list(on))) else: if left_index: if isinstance(left.index, MultiIndex): raise ValueError("left can only have one index") left_as_of_names = left._internal.index_spark_column_names else: left_as_of_names = list(map(left._internal.spark_column_name_for, to_list(left_on))) if right_index: if isinstance(right.index, MultiIndex): raise ValueError("right can only have one index") right_as_of_names = right._internal.index_spark_column_names else: right_as_of_names = list(map(right._internal.spark_column_name_for, to_list(right_on))) if left_as_of_names and not right_as_of_names: raise ValueError("Must pass right_on or right_index=True") if right_as_of_names and not left_as_of_names: raise ValueError("Must pass left_on or left_index=True") if not left_as_of_names and not right_as_of_names: common = list(left.columns.intersection(right.columns)) if len(common) == 0: raise ValueError( "No common columns to perform merge on. Merge options: " "left_on=None, right_on=None, left_index=False, right_index=False" ) left_as_of_names = list(map(left._internal.spark_column_name_for, to_list(common))) right_as_of_names = list(map(right._internal.spark_column_name_for, to_list(common))) if len(left_as_of_names) != 1: raise ValueError("can only asof on a key for left") if len(right_as_of_names) != 1: raise ValueError("can only asof on a key for right") if by: if left_by or right_by: raise ValueError('Can only pass argument "by" OR "left_by" and "right_by".') left_join_on_names = list(map(left._internal.spark_column_name_for, to_list(by))) right_join_on_names = list(map(right._internal.spark_column_name_for, to_list(by))) else: left_join_on_names = list(map(left._internal.spark_column_name_for, to_list(left_by))) right_join_on_names = list(map(right._internal.spark_column_name_for, to_list(right_by))) if left_join_on_names and not right_join_on_names: raise ValueError("missing right_by") if right_join_on_names and not left_join_on_names: raise ValueError("missing left_by") if len(left_join_on_names) != len(right_join_on_names): raise ValueError("left_by and right_by must be same length") # We should distinguish the name to avoid ambiguous column name after merging. right_prefix = "__right_" right_as_of_names = [right_prefix + right_as_of_name for right_as_of_name in right_as_of_names] right_join_on_names = [ right_prefix + right_join_on_name for right_join_on_name in right_join_on_names ] left_as_of_name = left_as_of_names[0] right_as_of_name = right_as_of_names[0] def resolve(internal: InternalFrame, side: str) -> InternalFrame: def rename(col: str) -> str: return "__{}_{}".format(side, col) internal = internal.resolved_copy sdf = internal.spark_frame sdf = sdf.select( *[ scol_for(sdf, col).alias(rename(col)) for col in sdf.columns if col not in HIDDEN_COLUMNS ], *HIDDEN_COLUMNS, ) return internal.copy( spark_frame=sdf, index_spark_columns=[ scol_for(sdf, rename(col)) for col in internal.index_spark_column_names ], index_fields=[field.copy(name=rename(field.name)) for field in internal.index_fields], data_spark_columns=[ scol_for(sdf, rename(col)) for col in internal.data_spark_column_names ], data_fields=[field.copy(name=rename(field.name)) for field in internal.data_fields], ) left_internal = left._internal.resolved_copy right_internal = resolve(right._internal, "right") left_table = left_internal.spark_frame.alias("left_table") right_table = right_internal.spark_frame.alias("right_table") left_as_of_column = scol_for(left_table, left_as_of_name) right_as_of_column = scol_for(right_table, right_as_of_name) if left_join_on_names: left_join_on_columns = [scol_for(left_table, label) for label in left_join_on_names] right_join_on_columns = [scol_for(right_table, label) for label in right_join_on_names] on = reduce( lambda lft, rgt: lft & rgt, [lft == rgt for lft, rgt in zip(left_join_on_columns, right_join_on_columns)], ) else: on = None Column = get_column_class() if tolerance is not None and not isinstance(tolerance, Column): tolerance = F.lit(tolerance) as_of_joined_table = left_table._joinAsOf( right_table, leftAsOfColumn=left_as_of_column, rightAsOfColumn=right_as_of_column, on=on, how="left", tolerance=tolerance, allowExactMatches=allow_exact_matches, direction=direction, ) # Unpack suffixes tuple for convenience left_suffix = suffixes[0] right_suffix = suffixes[1] # Append suffixes to columns with the same name to avoid conflicts later duplicate_columns = set(left_internal.column_labels) & set(right_internal.column_labels) exprs = [] data_columns = [] column_labels = [] def left_scol_for(label: Label) -> Column: # type: ignore[valid-type] return scol_for(as_of_joined_table, left_internal.spark_column_name_for(label)) def right_scol_for(label: Label) -> Column: # type: ignore[valid-type] return scol_for(as_of_joined_table, right_internal.spark_column_name_for(label)) for label in left_internal.column_labels: col = left_internal.spark_column_name_for(label) scol = left_scol_for(label) if label in duplicate_columns: spark_column_name = left_internal.spark_column_name_for(label) if spark_column_name in (left_as_of_names + left_join_on_names) and ( (right_prefix + spark_column_name) in (right_as_of_names + right_join_on_names) ): pass else: col = col + left_suffix scol = scol.alias(col) # type: ignore[attr-defined] label = tuple([str(label[0]) + left_suffix] + list(label[1:])) exprs.append(scol) data_columns.append(col) column_labels.append(label) for label in right_internal.column_labels: # recover `right_prefix` here. col = right_internal.spark_column_name_for(label)[len(right_prefix) :] scol = right_scol_for(label).alias(col) # type: ignore[attr-defined] if label in duplicate_columns: spark_column_name = left_internal.spark_column_name_for(label) if spark_column_name in left_as_of_names + left_join_on_names and ( (right_prefix + spark_column_name) in right_as_of_names + right_join_on_names ): continue else: col = col + right_suffix scol = scol.alias(col) # type: ignore[attr-defined] label = tuple([str(label[0]) + right_suffix] + list(label[1:])) exprs.append(scol) data_columns.append(col) column_labels.append(label) # Retain indices if they are used for joining if left_index or right_index: index_spark_column_names = [ SPARK_INDEX_NAME_FORMAT(i) for i in range(len(left_internal.index_spark_column_names)) ] left_index_scols = [ scol.alias(name) for scol, name in zip(left_internal.index_spark_columns, index_spark_column_names) ] exprs.extend(left_index_scols) index_names = left_internal.index_names else: index_spark_column_names = [] index_names = [] selected_columns = as_of_joined_table.select(*exprs) internal = InternalFrame( spark_frame=selected_columns, index_spark_columns=[scol_for(selected_columns, col) for col in index_spark_column_names], index_names=index_names, column_labels=column_labels, data_spark_columns=[scol_for(selected_columns, col) for col in data_columns], ) return DataFrame(internal)
[docs]@no_type_check def to_numeric(arg, errors="raise"): """ Convert argument to a numeric type. Parameters ---------- arg : scalar, list, tuple, 1-d array, or Series Argument to be converted. errors : {'raise', 'coerce'}, default 'raise' * If 'coerce', then invalid parsing will be set as NaN. * If 'raise', then invalid parsing will raise an exception. * If 'ignore', then invalid parsing will return the input. .. note:: 'ignore' doesn't work yet when `arg` is pandas-on-Spark Series. Returns ------- ret : numeric if parsing succeeded. See Also -------- DataFrame.astype : Cast argument to a specified dtype. to_datetime : Convert argument to datetime. to_timedelta : Convert argument to timedelta. numpy.ndarray.astype : Cast a numpy array to a specified type. Examples -------- >>> psser = ps.Series(['1.0', '2', '-3']) >>> psser 0 1.0 1 2 2 -3 dtype: object >>> ps.to_numeric(psser) 0 1.0 1 2.0 2 -3.0 dtype: float32 If given Series contains invalid value to cast float, just cast it to `np.nan` when `errors` is set to "coerce". >>> psser = ps.Series(['apple', '1.0', '2', '-3']) >>> psser 0 apple 1 1.0 2 2 3 -3 dtype: object >>> ps.to_numeric(psser, errors="coerce") 0 NaN 1 1.0 2 2.0 3 -3.0 dtype: float32 Also support for list, tuple, np.array, or a scalar >>> ps.to_numeric(['1.0', '2', '-3']) array([ 1., 2., -3.]) >>> ps.to_numeric(('1.0', '2', '-3')) array([ 1., 2., -3.]) >>> ps.to_numeric(np.array(['1.0', '2', '-3'])) array([ 1., 2., -3.]) >>> ps.to_numeric('1.0') 1.0 """ if isinstance(arg, Series): if errors == "coerce": return arg._with_new_scol(arg.spark.column.cast("float")) elif errors == "raise": scol = arg.spark.column scol_casted = scol.cast("float") cond = F.when( F.assert_true(scol.isNull() | scol_casted.isNotNull()).isNull(), scol_casted ) return arg._with_new_scol(cond) elif errors == "ignore": raise NotImplementedError("'ignore' is not implemented yet, when the `arg` is Series.") else: raise ValueError("invalid error value specified") else: return pd.to_numeric(arg, errors=errors)
[docs]def broadcast(obj: DataFrame) -> DataFrame: """ Marks a DataFrame as small enough for use in broadcast joins. .. deprecated:: 3.2.0 Use :func:`DataFrame.spark.hint` instead. Parameters ---------- obj : DataFrame Returns ------- ret : DataFrame with broadcast hint. See Also -------- DataFrame.merge : Merge DataFrame objects with a database-style join. DataFrame.join : Join columns of another DataFrame. DataFrame.update : Modify in place using non-NA values from another DataFrame. DataFrame.hint : Specifies some hint on the current DataFrame. Examples -------- >>> df1 = ps.DataFrame({'lkey': ['foo', 'bar', 'baz', 'foo'], ... 'value': [1, 2, 3, 5]}, ... columns=['lkey', 'value']).set_index('lkey') >>> df2 = ps.DataFrame({'rkey': ['foo', 'bar', 'baz', 'foo'], ... 'value': [5, 6, 7, 8]}, ... columns=['rkey', 'value']).set_index('rkey') >>> merged = df1.merge(ps.broadcast(df2), left_index=True, right_index=True) >>> merged.spark.explain() # doctest: +ELLIPSIS == Physical Plan == ... ...BroadcastHashJoin... ... """ warnings.warn( "`broadcast` has been deprecated and might be removed in a future version. " "Use `DataFrame.spark.hint` with 'broadcast' for `name` parameter instead.", FutureWarning, ) if not isinstance(obj, DataFrame): raise TypeError("Invalid type : expected DataFrame got {}".format(type(obj).__name__)) return DataFrame( obj._internal.with_new_sdf(F.broadcast(obj._internal.resolved_copy.spark_frame)) )
[docs]def read_orc( path: str, columns: Optional[List[str]] = None, index_col: Optional[Union[str, List[str]]] = None, **options: Any, ) -> "DataFrame": """ Load an ORC object from the file path, returning a DataFrame. Parameters ---------- path : str The path string storing the ORC file to be read. columns : list, default None If not None, only these columns will be read from the file. index_col : str or list of str, optional, default: None Index column of table in Spark. options : dict All other options passed directly into Spark's data source. Returns ------- DataFrame Examples -------- >>> ps.range(1).to_orc('%s/read_spark_io/data.orc' % path) >>> ps.read_orc('%s/read_spark_io/data.orc' % path, columns=['id']) id 0 0 You can preserve the index in the roundtrip as below. >>> ps.range(1).to_orc('%s/read_spark_io/data.orc' % path, index_col="index") >>> ps.read_orc('%s/read_spark_io/data.orc' % path, columns=['id'], index_col="index") ... # doctest: +NORMALIZE_WHITESPACE id index 0 0 """ if "options" in options and isinstance(options.get("options"), dict) and len(options) == 1: options = options.get("options") psdf = read_spark_io(path, format="orc", index_col=index_col, **options) if columns is not None: psdf_columns = psdf.columns new_columns = list() for column in list(columns): if column in psdf_columns: new_columns.append(column) else: raise ValueError("Unknown column name '{}'".format(column)) psdf = psdf[new_columns] return psdf
def _get_index_map( sdf: PySparkDataFrame, index_col: Optional[Union[str, List[str]]] = None ) -> Tuple[Optional[List[PySparkColumn]], Optional[List[Label]]]: index_spark_columns: Optional[List[PySparkColumn]] index_names: Optional[List[Label]] if index_col is not None: if isinstance(index_col, str): index_col = [index_col] sdf_columns = set(sdf.columns) for col in index_col: if col not in sdf_columns: raise KeyError(col) index_spark_columns = [scol_for(sdf, col) for col in index_col] index_names = [(col,) for col in index_col] else: index_spark_columns = None index_names = None return index_spark_columns, index_names _get_dummies_default_accept_types = (DecimalType, StringType, DateType) _get_dummies_acceptable_types = _get_dummies_default_accept_types + ( ByteType, ShortType, IntegerType, LongType, FloatType, DoubleType, BooleanType, TimestampType, TimestampNTZType, ) def _test() -> None: import os import doctest import shutil import sys import tempfile import uuid from pyspark.sql import SparkSession import pyspark.pandas.namespace os.chdir(os.environ["SPARK_HOME"]) globs = pyspark.pandas.namespace.__dict__.copy() globs["ps"] = pyspark.pandas globs["sf"] = F spark = ( SparkSession.builder.master("local[4]") .appName("pyspark.pandas.namespace tests") .getOrCreate() ) db_name = "db%s" % str(uuid.uuid4()).replace("-", "") spark.sql("CREATE DATABASE %s" % db_name) globs["db"] = db_name path = tempfile.mkdtemp() globs["path"] = path (failure_count, test_count) = doctest.testmod( pyspark.pandas.namespace, globs=globs, optionflags=doctest.ELLIPSIS | doctest.NORMALIZE_WHITESPACE, ) shutil.rmtree(path, ignore_errors=True) spark.sql("DROP DATABASE IF EXISTS %s CASCADE" % db_name) spark.stop() if failure_count: sys.exit(-1) if __name__ == "__main__": _test()