shared_docs.py

from typing import Dict

_shared_docs: Dict[str, str] = dict()

_shared_docs[
    "aggregate"
] = """\
Aggregate using one or more operations over the specified axis.

Parameters
----------
func : function, str, list or dict
    Function to use for aggregating the data. If a function, must either
    work when passed a {klass} or when passed to {klass}.apply.

    Accepted combinations are:

    - function
    - string function name
    - list of functions and/or function names, e.g. ``[np.sum, 'mean']``
    - dict of axis labels -> functions, function names or list of such.
{axis}
*args
    Positional arguments to pass to `func`.
**kwargs
    Keyword arguments to pass to `func`.

Returns
-------
scalar, Series or DataFrame

    The return can be:

    * scalar : when Series.agg is called with single function
    * Series : when DataFrame.agg is called with a single function
    * DataFrame : when DataFrame.agg is called with several functions

    Return scalar, Series or DataFrame.
{see_also}
Notes
-----
`agg` is an alias for `aggregate`. Use the alias.

A passed user-defined-function will be passed a Series for evaluation.
{examples}"""

_shared_docs[
    "compare"
] = """\
Compare to another %(klass)s and show the differences.

.. versionadded:: 1.1.0

Parameters
----------
other : %(klass)s
    Object to compare with.

align_axis : {0 or 'index', 1 or 'columns'}, default 1
    Determine which axis to align the comparison on.

    * 0, or 'index' : Resulting differences are stacked vertically
        with rows drawn alternately from self and other.
    * 1, or 'columns' : Resulting differences are aligned horizontally
        with columns drawn alternately from self and other.

keep_shape : bool, default False
    If true, all rows and columns are kept.
    Otherwise, only the ones with different values are kept.

keep_equal : bool, default False
    If true, the result keeps values that are equal.
    Otherwise, equal values are shown as NaNs.
"""

_shared_docs[
    "groupby"
] = """\
Group %(klass)s using a mapper or by a Series of columns.

A groupby operation involves some combination of splitting the
object, applying a function, and combining the results. This can be
used to group large amounts of data and compute operations on these
groups.

Parameters
----------
by : mapping, function, label, or list of labels
    Used to determine the groups for the groupby.
    If ``by`` is a function, it's called on each value of the object's
    index. If a dict or Series is passed, the Series or dict VALUES
    will be used to determine the groups (the Series' values are first
    aligned; see ``.align()`` method). If an ndarray is passed, the
    values are used as-is determine the groups. A label or list of
    labels may be passed to group by the columns in ``self``. Notice
    that a tuple is interpreted as a (single) key.
axis : {0 or 'index', 1 or 'columns'}, default 0
    Split along rows (0) or columns (1).
level : int, level name, or sequence of such, default None
    If the axis is a MultiIndex (hierarchical), group by a particular
    level or levels.
as_index : bool, default True
    For aggregated output, return object with group labels as the
    index. Only relevant for DataFrame input. as_index=False is
    effectively "SQL-style" grouped output.
sort : bool, default True
    Sort group keys. Get better performance by turning this off.
    Note this does not influence the order of observations within each
    group. Groupby preserves the order of rows within each group.
group_keys : bool, default True
    When calling apply, add group keys to index to identify pieces.
squeeze : bool, default False
    Reduce the dimensionality of the return type if possible,
    otherwise return a consistent type.

    .. deprecated:: 1.1.0

observed : bool, default False
    This only applies if any of the groupers are Categoricals.
    If True: only show observed values for categorical groupers.
    If False: show all values for categorical groupers.
dropna : bool, default True
    If True, and if group keys contain NA values, NA values together
    with row/column will be dropped.
    If False, NA values will also be treated as the key in groups

    .. versionadded:: 1.1.0

Returns
-------
%(klass)sGroupBy
    Returns a groupby object that contains information about the groups.

See Also
--------
resample : Convenience method for frequency conversion and resampling
    of time series.

Notes
-----
See the `user guide
<https://pandas.pydata.org/pandas-docs/stable/groupby.html>`_ for more.
"""

_shared_docs[
    "melt"
] = """\
Unpivot a DataFrame from wide to long format, optionally leaving identifiers set.

This function is useful to massage a DataFrame into a format where one
or more columns are identifier variables (`id_vars`), while all other
columns, considered measured variables (`value_vars`), are "unpivoted" to
the row axis, leaving just two non-identifier columns, 'variable' and
'value'.

Parameters
----------
id_vars : tuple, list, or ndarray, optional
    Column(s) to use as identifier variables.
value_vars : tuple, list, or ndarray, optional
    Column(s) to unpivot. If not specified, uses all columns that
    are not set as `id_vars`.
var_name : scalar
    Name to use for the 'variable' column. If None it uses
    ``frame.columns.name`` or 'variable'.
value_name : scalar, default 'value'
    Name to use for the 'value' column.
col_level : int or str, optional
    If columns are a MultiIndex then use this level to melt.
ignore_index : bool, default True
    If True, original index is ignored. If False, the original index is retained.
    Index labels will be repeated as necessary.

    .. versionadded:: 1.1.0

Returns
-------
DataFrame
    Unpivoted DataFrame.

See Also
--------
%(other)s : Identical method.
pivot_table : Create a spreadsheet-style pivot table as a DataFrame.
DataFrame.pivot : Return reshaped DataFrame organized
    by given index / column values.
DataFrame.explode : Explode a DataFrame from list-like
        columns to long format.

Examples
--------
>>> df = pd.DataFrame({'A': {0: 'a', 1: 'b', 2: 'c'},
...                    'B': {0: 1, 1: 3, 2: 5},
...                    'C': {0: 2, 1: 4, 2: 6}})
>>> df
   A  B  C
0  a  1  2
1  b  3  4
2  c  5  6

>>> %(caller)sid_vars=['A'], value_vars=['B'])
   A variable  value
0  a        B      1
1  b        B      3
2  c        B      5

>>> %(caller)sid_vars=['A'], value_vars=['B', 'C'])
   A variable  value
0  a        B      1
1  b        B      3
2  c        B      5
3  a        C      2
4  b        C      4
5  c        C      6

The names of 'variable' and 'value' columns can be customized:

>>> %(caller)sid_vars=['A'], value_vars=['B'],
...         var_name='myVarname', value_name='myValname')
   A myVarname  myValname
0  a         B          1
1  b         B          3
2  c         B          5

Original index values can be kept around:

>>> %(caller)sid_vars=['A'], value_vars=['B', 'C'], ignore_index=False)
   A variable  value
0  a        B      1
1  b        B      3
2  c        B      5
0  a        C      2
1  b        C      4
2  c        C      6

If you have multi-index columns:

>>> df.columns = [list('ABC'), list('DEF')]
>>> df
   A  B  C
   D  E  F
0  a  1  2
1  b  3  4
2  c  5  6

>>> %(caller)scol_level=0, id_vars=['A'], value_vars=['B'])
   A variable  value
0  a        B      1
1  b        B      3
2  c        B      5

>>> %(caller)sid_vars=[('A', 'D')], value_vars=[('B', 'E')])
  (A, D) variable_0 variable_1  value
0      a          B          E      1
1      b          B          E      3
2      c          B          E      5
"""

_shared_docs[
    "transform"
] = """\
Call ``func`` on self producing a {klass} with transformed values.

Produced {klass} will have same axis length as self.

Parameters
----------
func : function, str, list-like or dict-like
    Function to use for transforming the data. If a function, must either
    work when passed a {klass} or when passed to {klass}.apply. If func
    is both list-like and dict-like, dict-like behavior takes precedence.

    Accepted combinations are:

    - function
    - string function name
    - list-like of functions and/or function names, e.g. ``[np.exp, 'sqrt']``
    - dict-like of axis labels -> functions, function names or list-like of such.
{axis}
*args
    Positional arguments to pass to `func`.
**kwargs
    Keyword arguments to pass to `func`.

Returns
-------
{klass}
    A {klass} that must have the same length as self.

Raises
------
ValueError : If the returned {klass} has a different length than self.

See Also
--------
{klass}.agg : Only perform aggregating type operations.
{klass}.apply : Invoke function on a {klass}.

Examples
--------
>>> df = pd.DataFrame({{'A': range(3), 'B': range(1, 4)}})
>>> df
   A  B
0  0  1
1  1  2
2  2  3
>>> df.transform(lambda x: x + 1)
   A  B
0  1  2
1  2  3
2  3  4

Even though the resulting {klass} must have the same length as the
input {klass}, it is possible to provide several input functions:

>>> s = pd.Series(range(3))
>>> s
0    0
1    1
2    2
dtype: int64
>>> s.transform([np.sqrt, np.exp])
       sqrt        exp
0  0.000000   1.000000
1  1.000000   2.718282
2  1.414214   7.389056
"""