Map dataframe index using dictionary

Question

Why doesn\'t df.index.map(dict) work like df[\'column_name\'].map(dict)?

Here\'s a little example of trying to use index.map:

Answer 1

As of pandas version 0.23.x (released at May 15th, 2018) this problem is fixed:

import pandas as pd
pd.__version__        # 0.23.4

df = pd.DataFrame({'one': {'A': 10, 'B': 20, 'C': 30, 'D': 40, 'E': 50}})
map_dict = {'A': 'every', 'B': 'good', 'C': 'boy', 'D': 'does', 'E': 'fine'}
df
#    one
# A   10
# B   20
# C   30
# D   40
# E   50
df.index.map(map_dict)
#        one
# every   10
# good    20
# boy     30
# does    40
# fine    50

From the What's New page for pandas 0.23.0 it says:

Index.map() can now accept Series and dictionary input objects (GH12756, GH18482, GH18509).

For more information, check the help page of Index.map