pandas-匿名函數中的if...else

import pandas as pd
df = pd.DataFrame([[1,2],[3,5]],columns=['a','b'])
print(df)

   a  b
0  1  2
1  3  5

df['a'].apply(lambda x: 1 if x > 1 else 0)

   a  b
0  0  2
1  1  5