In Pandas sum columns and change values to proportion of sum

If I have the following DataFrame, how can I convert the value in each row to the proportion of the total of the columns?

Input:

pd.DataFrame(
{'A': {0: 1, 1: 1},
 'B': {0: 1, 1: 2},
 'C': {0: 1, 1: 9},})

Output:

pd.DataFrame(
{'A': {0: 0.5, 1: 0.5},
 'B': {0: 0.333, 1: 0.666},
 'C': {0: 1, 0.1: 0.9},})

Answer

How about apply?

import pandas as pd

df = pd.DataFrame(
{'A': {0: 1, 1: 1},
 'B': {0: 1, 1: 2},
 'C': {0: 1, 1: 9},})

df = df.apply(lambda col: col / sum(col))
print(df)
     # A         B    C
# 0  0.5  0.333333  0.1
# 1  0.5  0.666667  0.9