"""
|
Boilerplate functions used in defining binary operations.
|
"""
|
from __future__ import annotations
|
|
from functools import wraps
|
import sys
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from typing import Callable
|
|
from pandas._libs.lib import item_from_zerodim
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from pandas._libs.missing import is_matching_na
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from pandas._typing import F
|
|
from pandas.core.dtypes.generic import (
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ABCDataFrame,
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ABCIndex,
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ABCSeries,
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)
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|
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def unpack_zerodim_and_defer(name: str) -> Callable[[F], F]:
|
"""
|
Boilerplate for pandas conventions in arithmetic and comparison methods.
|
|
Parameters
|
----------
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name : str
|
|
Returns
|
-------
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decorator
|
"""
|
|
def wrapper(method: F) -> F:
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return _unpack_zerodim_and_defer(method, name)
|
|
return wrapper
|
|
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def _unpack_zerodim_and_defer(method, name: str):
|
"""
|
Boilerplate for pandas conventions in arithmetic and comparison methods.
|
|
Ensure method returns NotImplemented when operating against "senior"
|
classes. Ensure zero-dimensional ndarrays are always unpacked.
|
|
Parameters
|
----------
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method : binary method
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name : str
|
|
Returns
|
-------
|
method
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"""
|
if sys.version_info < (3, 9):
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from pandas.util._str_methods import (
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removeprefix,
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removesuffix,
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)
|
|
stripped_name = removesuffix(removeprefix(name, "__"), "__")
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else:
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stripped_name = name.removeprefix("__").removesuffix("__")
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is_cmp = stripped_name in {"eq", "ne", "lt", "le", "gt", "ge"}
|
|
@wraps(method)
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def new_method(self, other):
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if is_cmp and isinstance(self, ABCIndex) and isinstance(other, ABCSeries):
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# For comparison ops, Index does *not* defer to Series
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pass
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else:
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for cls in [ABCDataFrame, ABCSeries, ABCIndex]:
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if isinstance(self, cls):
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break
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if isinstance(other, cls):
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return NotImplemented
|
|
other = item_from_zerodim(other)
|
|
return method(self, other)
|
|
return new_method
|
|
|
def get_op_result_name(left, right):
|
"""
|
Find the appropriate name to pin to an operation result. This result
|
should always be either an Index or a Series.
|
|
Parameters
|
----------
|
left : {Series, Index}
|
right : object
|
|
Returns
|
-------
|
name : object
|
Usually a string
|
"""
|
if isinstance(right, (ABCSeries, ABCIndex)):
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name = _maybe_match_name(left, right)
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else:
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name = left.name
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return name
|
|
|
def _maybe_match_name(a, b):
|
"""
|
Try to find a name to attach to the result of an operation between
|
a and b. If only one of these has a `name` attribute, return that
|
name. Otherwise return a consensus name if they match or None if
|
they have different names.
|
|
Parameters
|
----------
|
a : object
|
b : object
|
|
Returns
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-------
|
name : str or None
|
|
See Also
|
--------
|
pandas.core.common.consensus_name_attr
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"""
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a_has = hasattr(a, "name")
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b_has = hasattr(b, "name")
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if a_has and b_has:
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try:
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if a.name == b.name:
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return a.name
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elif is_matching_na(a.name, b.name):
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# e.g. both are np.nan
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return a.name
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else:
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return None
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except TypeError:
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# pd.NA
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if is_matching_na(a.name, b.name):
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return a.name
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return None
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except ValueError:
|
# e.g. np.int64(1) vs (np.int64(1), np.int64(2))
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return None
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elif a_has:
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return a.name
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elif b_has:
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return b.name
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return None
|
