def _set_grouper(self, obj: FrameOrSeries, sort: bool = False):
"""
given an object and the specifications, setup the internal grouper
for this particular specification
Parameters
----------
obj : Series or DataFrame
sort : bool, default False
whether the resulting grouper should be sorted
"""
assert obj is not None
if self.key is not None and self.level is not None:
raise ValueError("The Grouper cannot specify both a key and a level!")
# Keep self.grouper value before overriding
if self._grouper is None:
self._grouper = self.grouper
# the key must be a valid info item
if self.key is not None:
key = self.key
# The 'on' is already defined
if getattr(self.grouper, "name", None) == key and isinstance(
obj, ABCSeries
):
# pandas\core\groupby\grouper.py:348: error: Item "None" of
# "Optional[Any]" has no attribute "take" [union-attr]
ax = self._grouper.take(obj.index) # type: ignore[union-attr]
else:
if key not in obj._info_axis:
raise KeyError(f"The grouper name {key} is not found")
ax = Index(obj[key], name=key)
else:
ax = obj._get_axis(self.axis)
if self.level is not None:
level = self.level
# if a level is given it must be a mi level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
ax = Index(ax._get_level_values(level), name=ax.names[level])
else:
if level not in (0, ax.name):
raise ValueError(f"The level {level} is not valid")
# possibly sort
if (self.sort or sort) and not ax.is_monotonic:
# use stable sort to support first, last, nth
indexer = self.indexer = ax.argsort(kind="mergesort")
ax = ax.take(indexer)
obj = obj.take(indexer, axis=self.axis)
self.obj = obj
self.grouper = ax
return self.grouper
def _set_grouper(self, obj: FrameOrSeries, sort: bool = False):
"""
given an object and the specifications, setup the internal grouper
for this particular specification
Parameters
----------
obj : Series or DataFrame
sort : bool, default False
whether the resulting grouper should be sorted
"""
assert obj is not None
if self.key is not None and self.level is not None:
raise ValueError(
"The Grouper cannot specify both a key and a level!")
# Keep self.grouper value before overriding
if self._grouper is None:
self._grouper = self.grouper
self._indexer = self.indexer
# the key must be a valid info item
if self.key is not None:
key = self.key
# The 'on' is already defined
if getattr(self.grouper, "name", None) == key and isinstance(
obj, Series):
# Sometimes self._grouper will have been resorted while
# obj has not. In this case there is a mismatch when we
# call self._grouper.take(obj.index) so we need to undo the sorting
# before we call _grouper.take.
assert self._grouper is not None
if self._indexer is not None:
reverse_indexer = self._indexer.argsort()
unsorted_ax = self._grouper.take(reverse_indexer)
ax = unsorted_ax.take(obj.index)
else:
ax = self._grouper.take(obj.index)
else:
if key not in obj._info_axis:
raise KeyError(f"The grouper name {key} is not found")
ax = Index(obj[key], name=key)
else:
ax = obj._get_axis(self.axis)
if self.level is not None:
level = self.level
# if a level is given it must be a mi level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
ax = Index(ax._get_level_values(level),
name=ax.names[level])
else:
if level not in (0, ax.name):
raise ValueError(f"The level {level} is not valid")
# possibly sort
if (self.sort or sort) and not ax.is_monotonic:
# use stable sort to support first, last, nth
# TODO: why does putting na_position="first" fix datetimelike cases?
indexer = self.indexer = ax.array.argsort(kind="mergesort",
na_position="first")
ax = ax.take(indexer)
obj = obj.take(indexer, axis=self.axis)
# error: Incompatible types in assignment (expression has type
# "FrameOrSeries", variable has type "None")
self.obj = obj # type: ignore[assignment]
# error: Incompatible types in assignment (expression has type "Index",
# variable has type "None")
self.grouper = ax # type: ignore[assignment]
return self.grouper
