Inzynierka/Lib/site-packages/pandas/core/window/expanding.py

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2023-06-02 12:51:02 +02:00
from __future__ import annotations
from textwrap import dedent
from typing import (
TYPE_CHECKING,
Any,
Callable,
)
from pandas._typing import (
Axis,
QuantileInterpolation,
WindowingRankType,
)
if TYPE_CHECKING:
from pandas import DataFrame, Series
from pandas.core.generic import NDFrame
from pandas.util._decorators import doc
from pandas.core.indexers.objects import (
BaseIndexer,
ExpandingIndexer,
GroupbyIndexer,
)
from pandas.core.window.doc import (
_shared_docs,
create_section_header,
kwargs_numeric_only,
numba_notes,
template_header,
template_returns,
template_see_also,
window_agg_numba_parameters,
window_apply_parameters,
)
from pandas.core.window.rolling import (
BaseWindowGroupby,
RollingAndExpandingMixin,
)
class Expanding(RollingAndExpandingMixin):
"""
Provide expanding window calculations.
Parameters
----------
min_periods : int, default 1
Minimum number of observations in window required to have a value;
otherwise, result is ``np.nan``.
axis : int or str, default 0
If ``0`` or ``'index'``, roll across the rows.
If ``1`` or ``'columns'``, roll across the columns.
For `Series` this parameter is unused and defaults to 0.
method : str {'single', 'table'}, default 'single'
Execute the rolling operation per single column or row (``'single'``)
or over the entire object (``'table'``).
This argument is only implemented when specifying ``engine='numba'``
in the method call.
.. versionadded:: 1.3.0
Returns
-------
``Expanding`` subclass
See Also
--------
rolling : Provides rolling window calculations.
ewm : Provides exponential weighted functions.
Notes
-----
See :ref:`Windowing Operations <window.expanding>` for further usage details
and examples.
Examples
--------
>>> df = pd.DataFrame({"B": [0, 1, 2, np.nan, 4]})
>>> df
B
0 0.0
1 1.0
2 2.0
3 NaN
4 4.0
**min_periods**
Expanding sum with 1 vs 3 observations needed to calculate a value.
>>> df.expanding(1).sum()
B
0 0.0
1 1.0
2 3.0
3 3.0
4 7.0
>>> df.expanding(3).sum()
B
0 NaN
1 NaN
2 3.0
3 3.0
4 7.0
"""
_attributes: list[str] = ["min_periods", "axis", "method"]
def __init__(
self,
obj: NDFrame,
min_periods: int = 1,
axis: Axis = 0,
method: str = "single",
selection=None,
) -> None:
super().__init__(
obj=obj,
min_periods=min_periods,
axis=axis,
method=method,
selection=selection,
)
def _get_window_indexer(self) -> BaseIndexer:
"""
Return an indexer class that will compute the window start and end bounds
"""
return ExpandingIndexer()
@doc(
_shared_docs["aggregate"],
see_also=dedent(
"""
See Also
--------
pandas.DataFrame.aggregate : Similar DataFrame method.
pandas.Series.aggregate : Similar Series method.
"""
),
examples=dedent(
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6], "C": [7, 8, 9]})
>>> df
A B C
0 1 4 7
1 2 5 8
2 3 6 9
>>> df.ewm(alpha=0.5).mean()
A B C
0 1.000000 4.000000 7.000000
1 1.666667 4.666667 7.666667
2 2.428571 5.428571 8.428571
"""
),
klass="Series/Dataframe",
axis="",
)
def aggregate(self, func, *args, **kwargs):
return super().aggregate(func, *args, **kwargs)
agg = aggregate
@doc(
template_header,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also[:-1],
window_method="expanding",
aggregation_description="count of non NaN observations",
agg_method="count",
)
def count(self, numeric_only: bool = False):
return super().count(numeric_only=numeric_only)
@doc(
template_header,
create_section_header("Parameters"),
window_apply_parameters,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also[:-1],
window_method="expanding",
aggregation_description="custom aggregation function",
agg_method="apply",
)
def apply(
self,
func: Callable[..., Any],
raw: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
args: tuple[Any, ...] | None = None,
kwargs: dict[str, Any] | None = None,
):
return super().apply(
func,
raw=raw,
engine=engine,
engine_kwargs=engine_kwargs,
args=args,
kwargs=kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
kwargs_numeric_only,
window_agg_numba_parameters(),
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also,
create_section_header("Notes"),
numba_notes[:-1],
window_method="expanding",
aggregation_description="sum",
agg_method="sum",
)
def sum(
self,
numeric_only: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
):
return super().sum(
numeric_only=numeric_only,
engine=engine,
engine_kwargs=engine_kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
kwargs_numeric_only,
window_agg_numba_parameters(),
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also,
create_section_header("Notes"),
numba_notes[:-1],
window_method="expanding",
aggregation_description="maximum",
agg_method="max",
)
def max(
self,
numeric_only: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
):
return super().max(
numeric_only=numeric_only,
engine=engine,
engine_kwargs=engine_kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
kwargs_numeric_only,
window_agg_numba_parameters(),
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also,
create_section_header("Notes"),
numba_notes[:-1],
window_method="expanding",
aggregation_description="minimum",
agg_method="min",
)
def min(
self,
numeric_only: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
):
return super().min(
numeric_only=numeric_only,
engine=engine,
engine_kwargs=engine_kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
kwargs_numeric_only,
window_agg_numba_parameters(),
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also,
create_section_header("Notes"),
numba_notes[:-1],
window_method="expanding",
aggregation_description="mean",
agg_method="mean",
)
def mean(
self,
numeric_only: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
):
return super().mean(
numeric_only=numeric_only,
engine=engine,
engine_kwargs=engine_kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
kwargs_numeric_only,
window_agg_numba_parameters(),
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also,
create_section_header("Notes"),
numba_notes[:-1],
window_method="expanding",
aggregation_description="median",
agg_method="median",
)
def median(
self,
numeric_only: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
):
return super().median(
numeric_only=numeric_only,
engine=engine,
engine_kwargs=engine_kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
dedent(
"""
ddof : int, default 1
Delta Degrees of Freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.\n
"""
).replace("\n", "", 1),
kwargs_numeric_only,
window_agg_numba_parameters("1.4"),
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
"numpy.std : Equivalent method for NumPy array.\n",
template_see_also,
create_section_header("Notes"),
dedent(
"""
The default ``ddof`` of 1 used in :meth:`Series.std` is different
than the default ``ddof`` of 0 in :func:`numpy.std`.
A minimum of one period is required for the rolling calculation.\n
"""
).replace("\n", "", 1),
create_section_header("Examples"),
dedent(
"""
>>> s = pd.Series([5, 5, 6, 7, 5, 5, 5])
>>> s.expanding(3).std()
0 NaN
1 NaN
2 0.577350
3 0.957427
4 0.894427
5 0.836660
6 0.786796
dtype: float64
"""
).replace("\n", "", 1),
window_method="expanding",
aggregation_description="standard deviation",
agg_method="std",
)
def std(
self,
ddof: int = 1,
numeric_only: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
):
return super().std(
ddof=ddof,
numeric_only=numeric_only,
engine=engine,
engine_kwargs=engine_kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
dedent(
"""
ddof : int, default 1
Delta Degrees of Freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.\n
"""
).replace("\n", "", 1),
kwargs_numeric_only,
window_agg_numba_parameters("1.4"),
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
"numpy.var : Equivalent method for NumPy array.\n",
template_see_also,
create_section_header("Notes"),
dedent(
"""
The default ``ddof`` of 1 used in :meth:`Series.var` is different
than the default ``ddof`` of 0 in :func:`numpy.var`.
A minimum of one period is required for the rolling calculation.\n
"""
).replace("\n", "", 1),
create_section_header("Examples"),
dedent(
"""
>>> s = pd.Series([5, 5, 6, 7, 5, 5, 5])
>>> s.expanding(3).var()
0 NaN
1 NaN
2 0.333333
3 0.916667
4 0.800000
5 0.700000
6 0.619048
dtype: float64
"""
).replace("\n", "", 1),
window_method="expanding",
aggregation_description="variance",
agg_method="var",
)
def var(
self,
ddof: int = 1,
numeric_only: bool = False,
engine: str | None = None,
engine_kwargs: dict[str, bool] | None = None,
):
return super().var(
ddof=ddof,
numeric_only=numeric_only,
engine=engine,
engine_kwargs=engine_kwargs,
)
@doc(
template_header,
create_section_header("Parameters"),
dedent(
"""
ddof : int, default 1
Delta Degrees of Freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.\n
"""
).replace("\n", "", 1),
kwargs_numeric_only,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also,
create_section_header("Notes"),
"A minimum of one period is required for the calculation.\n\n",
create_section_header("Examples"),
dedent(
"""
>>> s = pd.Series([0, 1, 2, 3])
>>> s.expanding().sem()
0 NaN
1 0.707107
2 0.707107
3 0.745356
dtype: float64
"""
).replace("\n", "", 1),
window_method="expanding",
aggregation_description="standard error of mean",
agg_method="sem",
)
def sem(self, ddof: int = 1, numeric_only: bool = False):
return super().sem(ddof=ddof, numeric_only=numeric_only)
@doc(
template_header,
create_section_header("Parameters"),
kwargs_numeric_only,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
"scipy.stats.skew : Third moment of a probability density.\n",
template_see_also,
create_section_header("Notes"),
"A minimum of three periods is required for the rolling calculation.\n",
window_method="expanding",
aggregation_description="unbiased skewness",
agg_method="skew",
)
def skew(self, numeric_only: bool = False):
return super().skew(numeric_only=numeric_only)
@doc(
template_header,
create_section_header("Parameters"),
kwargs_numeric_only,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
"scipy.stats.kurtosis : Reference SciPy method.\n",
template_see_also,
create_section_header("Notes"),
"A minimum of four periods is required for the calculation.\n\n",
create_section_header("Examples"),
dedent(
"""
The example below will show a rolling calculation with a window size of
four matching the equivalent function call using `scipy.stats`.
>>> arr = [1, 2, 3, 4, 999]
>>> import scipy.stats
>>> print(f"{{scipy.stats.kurtosis(arr[:-1], bias=False):.6f}}")
-1.200000
>>> print(f"{{scipy.stats.kurtosis(arr, bias=False):.6f}}")
4.999874
>>> s = pd.Series(arr)
>>> s.expanding(4).kurt()
0 NaN
1 NaN
2 NaN
3 -1.200000
4 4.999874
dtype: float64
"""
).replace("\n", "", 1),
window_method="expanding",
aggregation_description="Fisher's definition of kurtosis without bias",
agg_method="kurt",
)
def kurt(self, numeric_only: bool = False):
return super().kurt(numeric_only=numeric_only)
@doc(
template_header,
create_section_header("Parameters"),
dedent(
"""
quantile : float
Quantile to compute. 0 <= quantile <= 1.
interpolation : {{'linear', 'lower', 'higher', 'midpoint', 'nearest'}}
This optional parameter specifies the interpolation method to use,
when the desired quantile lies between two data points `i` and `j`:
* linear: `i + (j - i) * fraction`, where `fraction` is the
fractional part of the index surrounded by `i` and `j`.
* lower: `i`.
* higher: `j`.
* nearest: `i` or `j` whichever is nearest.
* midpoint: (`i` + `j`) / 2.
"""
).replace("\n", "", 1),
kwargs_numeric_only,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also[:-1],
window_method="expanding",
aggregation_description="quantile",
agg_method="quantile",
)
def quantile(
self,
quantile: float,
interpolation: QuantileInterpolation = "linear",
numeric_only: bool = False,
):
return super().quantile(
quantile=quantile,
interpolation=interpolation,
numeric_only=numeric_only,
)
@doc(
template_header,
".. versionadded:: 1.4.0 \n\n",
create_section_header("Parameters"),
dedent(
"""
method : {{'average', 'min', 'max'}}, default 'average'
How to rank the group of records that have the same value (i.e. ties):
* average: average rank of the group
* min: lowest rank in the group
* max: highest rank in the group
ascending : bool, default True
Whether or not the elements should be ranked in ascending order.
pct : bool, default False
Whether or not to display the returned rankings in percentile
form.
"""
).replace("\n", "", 1),
kwargs_numeric_only,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also,
create_section_header("Examples"),
dedent(
"""
>>> s = pd.Series([1, 4, 2, 3, 5, 3])
>>> s.expanding().rank()
0 1.0
1 2.0
2 2.0
3 3.0
4 5.0
5 3.5
dtype: float64
>>> s.expanding().rank(method="max")
0 1.0
1 2.0
2 2.0
3 3.0
4 5.0
5 4.0
dtype: float64
>>> s.expanding().rank(method="min")
0 1.0
1 2.0
2 2.0
3 3.0
4 5.0
5 3.0
dtype: float64
"""
).replace("\n", "", 1),
window_method="expanding",
aggregation_description="rank",
agg_method="rank",
)
def rank(
self,
method: WindowingRankType = "average",
ascending: bool = True,
pct: bool = False,
numeric_only: bool = False,
):
return super().rank(
method=method,
ascending=ascending,
pct=pct,
numeric_only=numeric_only,
)
@doc(
template_header,
create_section_header("Parameters"),
dedent(
"""
other : Series or DataFrame, optional
If not supplied then will default to self and produce pairwise
output.
pairwise : bool, default None
If False then only matching columns between self and other will be
used and the output will be a DataFrame.
If True then all pairwise combinations will be calculated and the
output will be a MultiIndexed DataFrame in the case of DataFrame
inputs. In the case of missing elements, only complete pairwise
observations will be used.
ddof : int, default 1
Delta Degrees of Freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.
"""
).replace("\n", "", 1),
kwargs_numeric_only,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
template_see_also[:-1],
window_method="expanding",
aggregation_description="sample covariance",
agg_method="cov",
)
def cov(
self,
other: DataFrame | Series | None = None,
pairwise: bool | None = None,
ddof: int = 1,
numeric_only: bool = False,
):
return super().cov(
other=other,
pairwise=pairwise,
ddof=ddof,
numeric_only=numeric_only,
)
@doc(
template_header,
create_section_header("Parameters"),
dedent(
"""
other : Series or DataFrame, optional
If not supplied then will default to self and produce pairwise
output.
pairwise : bool, default None
If False then only matching columns between self and other will be
used and the output will be a DataFrame.
If True then all pairwise combinations will be calculated and the
output will be a MultiIndexed DataFrame in the case of DataFrame
inputs. In the case of missing elements, only complete pairwise
observations will be used.
"""
).replace("\n", "", 1),
kwargs_numeric_only,
create_section_header("Returns"),
template_returns,
create_section_header("See Also"),
dedent(
"""
cov : Similar method to calculate covariance.
numpy.corrcoef : NumPy Pearson's correlation calculation.
"""
).replace("\n", "", 1),
template_see_also,
create_section_header("Notes"),
dedent(
"""
This function uses Pearson's definition of correlation
(https://en.wikipedia.org/wiki/Pearson_correlation_coefficient).
When `other` is not specified, the output will be self correlation (e.g.
all 1's), except for :class:`~pandas.DataFrame` inputs with `pairwise`
set to `True`.
Function will return ``NaN`` for correlations of equal valued sequences;
this is the result of a 0/0 division error.
When `pairwise` is set to `False`, only matching columns between `self` and
`other` will be used.
When `pairwise` is set to `True`, the output will be a MultiIndex DataFrame
with the original index on the first level, and the `other` DataFrame
columns on the second level.
In the case of missing elements, only complete pairwise observations
will be used.
"""
).replace("\n", "", 1),
window_method="expanding",
aggregation_description="correlation",
agg_method="corr",
)
def corr(
self,
other: DataFrame | Series | None = None,
pairwise: bool | None = None,
ddof: int = 1,
numeric_only: bool = False,
):
return super().corr(
other=other,
pairwise=pairwise,
ddof=ddof,
numeric_only=numeric_only,
)
class ExpandingGroupby(BaseWindowGroupby, Expanding):
"""
Provide a expanding groupby implementation.
"""
_attributes = Expanding._attributes + BaseWindowGroupby._attributes
def _get_window_indexer(self) -> GroupbyIndexer:
"""
Return an indexer class that will compute the window start and end bounds
Returns
-------
GroupbyIndexer
"""
window_indexer = GroupbyIndexer(
groupby_indices=self._grouper.indices,
window_indexer=ExpandingIndexer,
)
return window_indexer