1>>> df['C'] = df['C'].apply(np.int64)
2>>> print(df)
3... A B C D
4... 0 8 0 1 6.226750
5... 1 1 9 9 8.522808
6... 2 1 4 2 7.739108
1>>> df
2 A B C D
30 0.475103 0.355453 0.66 0.869336
41 0.260395 0.200287 NaN 0.617024
52 0.517692 0.735613 0.18 0.657106
6>>> df[list("ABCD")] = df[list("ABCD")].fillna(0.0).astype(int)
7>>> df
8 A B C D
90 0 0 0 0
101 0 0 0 0
112 0 0 0 0