pandas.Index.map

Index.map(mapper, na_action=None)[source]

Map values using an input mapping or function.

Parameters:
mapperfunction, dict, or Series

Mapping correspondence.

na_action{None, ‘ignore’}

If ‘ignore’, propagate NA values, without passing them to the mapping correspondence.

Returns:
appliedUnion[Index, MultiIndex], inferred

The output of the mapping function applied to the index. If the function returns a tuple with more than one element a MultiIndex will be returned.