spark-instrumented-optimizer/python/pyspark/pandas/indexes/category.py
Takuya UESHIN 376fadc89c [SPARK-36186][PYTHON] Add as_ordered/as_unordered to CategoricalAccessor and CategoricalIndex
### What changes were proposed in this pull request?

Add `as_ordered`/`as_unordered` to `CategoricalAccessor` and `CategoricalIndex`.

### Why are the changes needed?

We should implement `as_ordered`/`as_unordered` in `CategoricalAccessor` and `CategoricalIndex` yet.

### Does this PR introduce _any_ user-facing change?

Yes, users will be able to use `as_ordered`/`as_unordered`.

### How was this patch tested?

Added some tests.

Closes #33400 from ueshin/issues/SPARK-36186/as_ordered_unordered.

Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
2021-07-20 18:23:54 -07:00

297 lines
10 KiB
Python

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from functools import partial
from typing import Any, Optional, cast, no_type_check
import pandas as pd
from pandas.api.types import is_hashable, CategoricalDtype
from pyspark import pandas as ps
from pyspark.pandas.indexes.base import Index
from pyspark.pandas.internal import InternalField
from pyspark.pandas.missing.indexes import MissingPandasLikeCategoricalIndex
from pyspark.pandas.series import Series
from pyspark.sql.types import StructField
class CategoricalIndex(Index):
"""
Index based on an underlying `Categorical`.
CategoricalIndex can only take on a limited,
and usually fixed, number of possible values (`categories`). Also,
it might have an order, but numerical operations
(additions, divisions, ...) are not possible.
Parameters
----------
data : array-like (1-dimensional)
The values of the categorical. If `categories` are given, values not in
`categories` will be replaced with NaN.
categories : index-like, optional
The categories for the categorical. Items need to be unique.
If the categories are not given here (and also not in `dtype`), they
will be inferred from the `data`.
ordered : bool, optional
Whether or not this categorical is treated as an ordered
categorical. If not given here or in `dtype`, the resulting
categorical will be unordered.
dtype : CategoricalDtype or "category", optional
If :class:`CategoricalDtype`, cannot be used together with
`categories` or `ordered`.
copy : bool, default False
Make a copy of input ndarray.
name : object, optional
Name to be stored in the index.
See Also
--------
Index : The base pandas-on-Spark Index type.
Examples
--------
>>> ps.CategoricalIndex(["a", "b", "c", "a", "b", "c"]) # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'c', 'a', 'b', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
``CategoricalIndex`` can also be instantiated from a ``Categorical``:
>>> c = pd.Categorical(["a", "b", "c", "a", "b", "c"])
>>> ps.CategoricalIndex(c) # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'c', 'a', 'b', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
Ordered ``CategoricalIndex`` can have a min and max value.
>>> ci = ps.CategoricalIndex(
... ["a", "b", "c", "a", "b", "c"], ordered=True, categories=["c", "b", "a"]
... )
>>> ci # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'c', 'a', 'b', 'c'],
categories=['c', 'b', 'a'], ordered=True, dtype='category')
From a Series:
>>> s = ps.Series(["a", "b", "c", "a", "b", "c"], index=[10, 20, 30, 40, 50, 60])
>>> ps.CategoricalIndex(s) # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'c', 'a', 'b', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
From an Index:
>>> idx = ps.Index(["a", "b", "c", "a", "b", "c"])
>>> ps.CategoricalIndex(idx) # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'c', 'a', 'b', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
"""
@no_type_check
def __new__(cls, data=None, categories=None, ordered=None, dtype=None, copy=False, name=None):
if not is_hashable(name):
raise TypeError("Index.name must be a hashable type")
if isinstance(data, (Series, Index)):
if dtype is None:
dtype = "category"
return Index(data, dtype=dtype, copy=copy, name=name)
return ps.from_pandas(
pd.CategoricalIndex(
data=data, categories=categories, ordered=ordered, dtype=dtype, name=name
)
)
@property
def dtype(self) -> CategoricalDtype:
return cast(CategoricalDtype, super().dtype)
@property
def codes(self) -> Index:
"""
The category codes of this categorical.
Codes are an Index of integers which are the positions of the actual
values in the categories Index.
There is no setter, use the other categorical methods and the normal item
setter to change values in the categorical.
Returns
-------
Index
A non-writable view of the `codes` Index.
Examples
--------
>>> idx = ps.CategoricalIndex(list("abbccc"))
>>> idx # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
>>> idx.codes
Int64Index([0, 1, 1, 2, 2, 2], dtype='int64')
"""
return self._with_new_scol(
self.spark.column,
field=InternalField.from_struct_field(
StructField(
name=self._internal.index_spark_column_names[0],
dataType=self.spark.data_type,
nullable=self.spark.nullable,
)
),
).rename(None)
@property
def categories(self) -> pd.Index:
"""
The categories of this categorical.
Examples
--------
>>> idx = ps.CategoricalIndex(list("abbccc"))
>>> idx # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
>>> idx.categories
Index(['a', 'b', 'c'], dtype='object')
"""
return self.dtype.categories
@categories.setter
def categories(self, categories: pd.Index) -> None:
raise NotImplementedError()
@property
def ordered(self) -> bool:
"""
Whether the categories have an ordered relationship.
Examples
--------
>>> idx = ps.CategoricalIndex(list("abbccc"))
>>> idx # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
>>> idx.ordered
False
"""
return self.dtype.ordered
def as_ordered(self, inplace: bool = False) -> Optional["CategoricalIndex"]:
"""
Set the Categorical to be ordered.
Parameters
----------
inplace : bool, default False
Whether or not to set the ordered attribute in-place or return
a copy of this categorical with ordered set to True.
Returns
-------
CategoricalIndex or None
Ordered Categorical or None if ``inplace=True``.
Examples
--------
>>> idx = ps.CategoricalIndex(list("abbccc"))
>>> idx # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
>>> idx.as_ordered() # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'],
categories=['a', 'b', 'c'], ordered=True, dtype='category')
"""
if inplace:
raise ValueError("cannot use inplace with CategoricalIndex")
return CategoricalIndex(self.to_series().cat.as_ordered()).rename(self.name)
def as_unordered(self, inplace: bool = False) -> Optional["CategoricalIndex"]:
"""
Set the Categorical to be unordered.
Parameters
----------
inplace : bool, default False
Whether or not to set the ordered attribute in-place or return
a copy of this categorical with ordered set to False.
Returns
-------
CategoricalIndex or None
Unordered Categorical or None if ``inplace=True``.
Examples
--------
>>> idx = ps.CategoricalIndex(list("abbccc")).as_ordered()
>>> idx # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'],
categories=['a', 'b', 'c'], ordered=True, dtype='category')
>>> idx.as_unordered() # doctest: +NORMALIZE_WHITESPACE
CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'],
categories=['a', 'b', 'c'], ordered=False, dtype='category')
"""
if inplace:
raise ValueError("cannot use inplace with CategoricalIndex")
return CategoricalIndex(self.to_series().cat.as_unordered()).rename(self.name)
def __getattr__(self, item: str) -> Any:
if hasattr(MissingPandasLikeCategoricalIndex, item):
property_or_func = getattr(MissingPandasLikeCategoricalIndex, item)
if isinstance(property_or_func, property):
return property_or_func.fget(self) # type: ignore
else:
return partial(property_or_func, self)
raise AttributeError("'CategoricalIndex' object has no attribute '{}'".format(item))
def _test() -> None:
import os
import doctest
import sys
from pyspark.sql import SparkSession
import pyspark.pandas.indexes.category
os.chdir(os.environ["SPARK_HOME"])
globs = pyspark.pandas.indexes.category.__dict__.copy()
globs["ps"] = pyspark.pandas
spark = (
SparkSession.builder.master("local[4]")
.appName("pyspark.pandas.indexes.category tests")
.getOrCreate()
)
(failure_count, test_count) = doctest.testmod(
pyspark.pandas.indexes.category,
globs=globs,
optionflags=doctest.ELLIPSIS | doctest.NORMALIZE_WHITESPACE,
)
spark.stop()
if failure_count:
sys.exit(-1)
if __name__ == "__main__":
_test()