rename column based on index in python code example

Example 1: how to change column name in pandas

print(df.rename(columns={'A': 'a', 'C': 'c'}))
#         a   B   c
# ONE    11  12  13
# TWO    21  22  23
# THREE  31  32  33

Example 2: rename dataframe index column pandas

df.index.names = ['new_name']