pandas.Index.set_names#

Index.set_names(names, *, level=None, inplace=False)[source]#

Set Index or MultiIndex name.

Able to set new names partially and by level.

Parameters

nameslabel or list of label or dict-like for MultiIndex: Name(s) to set.

Changed in version 1.3.0.
levelint, label or list of int or label, optional: If the index is a MultiIndex and names is not dict-like, level(s) to set (None for all levels). Otherwise level must be None.

Changed in version 1.3.0.
inplacebool, default False: Modifies the object directly, instead of creating a new Index or MultiIndex.

Returns

Index or None: The same type as the caller or None if inplace=True.

See also

Index.rename: Able to set new names without level.

Examples

>>> idx = pd.Index([1, 2, 3, 4])
>>> idx
Int64Index([1, 2, 3, 4], dtype='int64')
>>> idx.set_names('quarter')
Int64Index([1, 2, 3, 4], dtype='int64', name='quarter')

>>> idx = pd.MultiIndex.from_product([['python', 'cobra'],
...                                   [2018, 2019]])
>>> idx
MultiIndex([('python', 2018),
            ('python', 2019),
            ( 'cobra', 2018),
            ( 'cobra', 2019)],
           )
>>> idx.set_names(['kind', 'year'], inplace=True)
>>> idx
MultiIndex([('python', 2018),
            ('python', 2019),
            ( 'cobra', 2018),
            ( 'cobra', 2019)],
           names=['kind', 'year'])
>>> idx.set_names('species', level=0)
MultiIndex([('python', 2018),
            ('python', 2019),
            ( 'cobra', 2018),
            ( 'cobra', 2019)],
           names=['species', 'year'])

When renaming levels with a dict, levels can not be passed.

>>> idx.set_names({'kind': 'snake'})
MultiIndex([('python', 2018),
            ('python', 2019),
            ( 'cobra', 2018),
            ( 'cobra', 2019)],
           names=['snake', 'year'])