pandas.MultiIndex.is_lexsorted

MultiIndex.is_lexsorted(self) → bool

Return True if the codes are lexicographically sorted.

Returns

bool

Examples

In the below examples, the first level of the MultiIndex is sorted because a<b<c, so there is no need to look at the next level.

>>> pd.MultiIndex.from_arrays([['a', 'b', 'c'], ['d', 'e', 'f']]).is_lexsorted()
True
>>> pd.MultiIndex.from_arrays([['a', 'b', 'c'], ['d', 'f', 'e']]).is_lexsorted()
True

In case there is a tie, the lexicographical sorting looks at the next level of the MultiIndex.

>>> pd.MultiIndex.from_arrays([[0, 1, 1], ['a', 'b', 'c']]).is_lexsorted()
True
>>> pd.MultiIndex.from_arrays([[0, 1, 1], ['a', 'c', 'b']]).is_lexsorted()
False
>>> pd.MultiIndex.from_arrays([['a', 'a', 'b', 'b'],
...                            ['aa', 'bb', 'aa', 'bb']]).is_lexsorted()
True
>>> pd.MultiIndex.from_arrays([['a', 'a', 'b', 'b'],
...                            ['bb', 'aa', 'aa', 'bb']]).is_lexsorted()
False

pandas.MultiIndex.to_flat_index pandas.MultiIndex.sortlevel