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Fonction merge_ordered - module pandas

Signature de la fonction merge_ordered

def merge_ordered(left, right, on=None, left_on=None, right_on=None, left_by=None, right_by=None, fill_method=None, suffixes=('_x', '_y'), how: str = 'outer') -> 'DataFrame' 

Description

merge_ordered.__doc__

    Perform merge with optional filling/interpolation.

    Designed for ordered data like time series data. Optionally
    perform group-wise merge (see examples).

    Parameters
    ----------
    left : DataFrame
    right : DataFrame
    on : label or list
        Field names to join on. Must be found in both DataFrames.
    left_on : label or list, or array-like
        Field names to join on in left DataFrame. Can be a vector or list of
        vectors of the length of the DataFrame to use a particular vector as
        the join key instead of columns.
    right_on : label or list, or array-like
        Field names to join on in right DataFrame or vector/list of vectors per
        left_on docs.
    left_by : column name or list of column names
        Group left DataFrame by group columns and merge piece by piece with
        right DataFrame.
    right_by : column name or list of column names
        Group right DataFrame by group columns and merge piece by piece with
        left DataFrame.
    fill_method : {'ffill', None}, default None
        Interpolation method for data.
    suffixes : list-like, default is ("_x", "_y")
        A length-2 sequence where each element is optionally a string
        indicating the suffix to add to overlapping column names in
        `left` and `right` respectively. Pass a value of `None` instead
        of a string to indicate that the column name from `left` or
        `right` should be left as-is, with no suffix. At least one of the
        values must not be None.

        .. versionchanged:: 0.25.0
    how : {'left', 'right', 'outer', 'inner'}, default 'outer'
        * left: use only keys from left frame (SQL: left outer join)
        * right: use only keys from right frame (SQL: right outer join)
        * outer: use union of keys from both frames (SQL: full outer join)
        * inner: use intersection of keys from both frames (SQL: inner join).

    Returns
    -------
    DataFrame
        The merged DataFrame output type will the be same as
        'left', if it is a subclass of DataFrame.

    See Also
    --------
    merge : Merge with a database-style join.
    merge_asof : Merge on nearest keys.

    Examples
    --------
    >>> df1 = pd.DataFrame(
    ...     {
    ...         "key": ["a", "c", "e", "a", "c", "e"],
    ...         "lvalue": [1, 2, 3, 1, 2, 3],
    ...         "group": ["a", "a", "a", "b", "b", "b"]
    ...     }
    ... )
    >>> df1
          key  lvalue group
    0   a       1     a
    1   c       2     a
    2   e       3     a
    3   a       1     b
    4   c       2     b
    5   e       3     b

    >>> df2 = pd.DataFrame({"key": ["b", "c", "d"], "rvalue": [1, 2, 3]})
    >>> df2
          key  rvalue
    0   b       1
    1   c       2
    2   d       3

    >>> merge_ordered(df1, df2, fill_method="ffill", left_by="group")
      key  lvalue group  rvalue
    0   a       1     a     NaN
    1   b       1     a     1.0
    2   c       2     a     2.0
    3   d       2     a     3.0
    4   e       3     a     3.0
    5   a       1     b     NaN
    6   b       1     b     1.0
    7   c       2     b     2.0
    8   d       2     b     3.0
    9   e       3     b     3.0