projektAI/venv/Lib/site-packages/pandas/core/array_algos/masked_reductions.py
2021-06-06 22:13:05 +02:00

110 lines
3.0 KiB
Python

"""
masked_reductions.py is for reduction algorithms using a mask-based approach
for missing values.
"""
from typing import Callable
import numpy as np
from pandas._libs import missing as libmissing
from pandas.compat.numpy import np_version_under1p17
from pandas.core.nanops import check_below_min_count
def _sumprod(
func: Callable,
values: np.ndarray,
mask: np.ndarray,
*,
skipna: bool = True,
min_count: int = 0,
):
"""
Sum or product for 1D masked array.
Parameters
----------
func : np.sum or np.prod
values : np.ndarray
Numpy array with the values (can be of any dtype that support the
operation).
mask : np.ndarray
Boolean numpy array (True values indicate missing values).
skipna : bool, default True
Whether to skip NA.
min_count : int, default 0
The required number of valid values to perform the operation. If fewer than
``min_count`` non-NA values are present the result will be NA.
"""
if not skipna:
if mask.any() or check_below_min_count(values.shape, None, min_count):
return libmissing.NA
else:
return func(values)
else:
if check_below_min_count(values.shape, mask, min_count):
return libmissing.NA
if np_version_under1p17:
return func(values[~mask])
else:
return func(values, where=~mask)
def sum(
values: np.ndarray, mask: np.ndarray, *, skipna: bool = True, min_count: int = 0
):
return _sumprod(
np.sum, values=values, mask=mask, skipna=skipna, min_count=min_count
)
def prod(
values: np.ndarray, mask: np.ndarray, *, skipna: bool = True, min_count: int = 0
):
return _sumprod(
np.prod, values=values, mask=mask, skipna=skipna, min_count=min_count
)
def _minmax(
func: Callable, values: np.ndarray, mask: np.ndarray, *, skipna: bool = True
):
"""
Reduction for 1D masked array.
Parameters
----------
func : np.min or np.max
values : np.ndarray
Numpy array with the values (can be of any dtype that support the
operation).
mask : np.ndarray
Boolean numpy array (True values indicate missing values).
skipna : bool, default True
Whether to skip NA.
"""
if not skipna:
if mask.any() or not values.size:
# min/max with empty array raise in numpy, pandas returns NA
return libmissing.NA
else:
return func(values)
else:
subset = values[~mask]
if subset.size:
return func(subset)
else:
# min/max with empty array raise in numpy, pandas returns NA
return libmissing.NA
def min(values: np.ndarray, mask: np.ndarray, *, skipna: bool = True):
return _minmax(np.min, values=values, mask=mask, skipna=skipna)
def max(values: np.ndarray, mask: np.ndarray, *, skipna: bool = True):
return _minmax(np.max, values=values, mask=mask, skipna=skipna)