pandas set one column equal to another
In [300]:
df.loc[df['colA'] == 'a', 'colC'] = df['colB']
df['colC'] = df['colC'].fillna(0)
df
Out[300]:
id colA colB colC
0 0 a 13 13
1 1 a 52 52
2 2 b 16 0
3 3 a 34 34
4 4 b 946 0