pandas.MultiIndex.set_levels#

MultiIndex.set_levels(levels, *, level=None, inplace=None, verify_integrity=True)[source]#

Set new levels on MultiIndex. Defaults to returning new index.

Parameters

levelssequence or list of sequence: New level(s) to apply.
levelint, level name, or sequence of int/level names (default None): Level(s) to set (None for all levels).
inplacebool: If True, mutates in place.

Deprecated since version 1.2.0.
verify_integritybool, default True: If True, checks that levels and codes are compatible.

Returns

new index (of same type and class…etc) or None: The same type as the caller or None if inplace=True.

Examples

>>> idx = pd.MultiIndex.from_tuples(
...     [
...         (1, "one"),
...         (1, "two"),
...         (2, "one"),
...         (2, "two"),
...         (3, "one"),
...         (3, "two")
...     ],
...     names=["foo", "bar"]
... )
>>> idx
MultiIndex([(1, 'one'),
    (1, 'two'),
    (2, 'one'),
    (2, 'two'),
    (3, 'one'),
    (3, 'two')],
   names=['foo', 'bar'])

>>> idx.set_levels([['a', 'b', 'c'], [1, 2]])
MultiIndex([('a', 1),
            ('a', 2),
            ('b', 1),
            ('b', 2),
            ('c', 1),
            ('c', 2)],
           names=['foo', 'bar'])
>>> idx.set_levels(['a', 'b', 'c'], level=0)
MultiIndex([('a', 'one'),
            ('a', 'two'),
            ('b', 'one'),
            ('b', 'two'),
            ('c', 'one'),
            ('c', 'two')],
           names=['foo', 'bar'])
>>> idx.set_levels(['a', 'b'], level='bar')
MultiIndex([(1, 'a'),
            (1, 'b'),
            (2, 'a'),
            (2, 'b'),
            (3, 'a'),
            (3, 'b')],
           names=['foo', 'bar'])

If any of the levels passed to set_levels() exceeds the existing length, all of the values from that argument will be stored in the MultiIndex levels, though the values will be truncated in the MultiIndex output.

>>> idx.set_levels([['a', 'b', 'c'], [1, 2, 3, 4]], level=[0, 1])
MultiIndex([('a', 1),
    ('a', 2),
    ('b', 1),
    ('b', 2),
    ('c', 1),
    ('c', 2)],
   names=['foo', 'bar'])
>>> idx.set_levels([['a', 'b', 'c'], [1, 2, 3, 4]], level=[0, 1]).levels
FrozenList([['a', 'b', 'c'], [1, 2, 3, 4]])