how to change the name of the index in pandas code example

Example 1: rename column pandas

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

print(df)
#         A   B   C
# ONE    11  12  13
# TWO    21  22  23
# THREE  31  32  33

Example 2: df reanme columns

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