在dataframe多列元素操作（Pandas）

Question

给定一个DataFrame df，我想做类似的事情：

if df['one'] >= df['two']:
    df['three'] = df['four']
    df['five'] = df['two'] / df['four']

Answer 1

将.loc属性与布尔索引一起使用。

condition = df.one >= df.two
df.loc[condition, 'three'] = df['four']
df.loc[condition, 'five'] = df['two'] / df['four']