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

levels:sequence or list of sequence

New level(s) to apply.

level:int, level name, or sequence of int/level names (default None)

Level(s) to set (None for all levels).

inplace:bool

If True, mutates in place.

Deprecated since version 1.2.0.

verify_integrity:bool, 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]])