Pandas DataFrame条件赋值问题：非指定州佣金率设置求助

你的第二行代码逻辑错误：用|（逻辑或）会导致所有行都被匹配——任何州必然满足「不等于CA」「不等于NV」「不等于HI」中的至少一个（比如CA不等于NV），所以所有行都会被重新赋值为0.035，直接覆盖了第一行的结果。

修正方案1：修正逻辑运算符 #

把第二行的|换成&（逻辑与），表示同时满足「不是CA」「不是NV」「不是HI」：

import pandas as pd
import numpy as np

repone.loc[(repone['State'] == 'CA') | (repone['State'] == 'NV') | (repone['State'] == 'HI'), 'Commission %'] = .07
repone.loc[(repone['State'] != 'CA') & (repone['State'] != 'NV') & (repone['State'] != 'HI'), 'Commission %'] = .035

修正方案2：用isin简化代码 #

更简洁易读的写法是用isin判断是否在指定州列表里，再通过~取反匹配其他州：

import pandas as pd
import numpy as np

target_states = ['CA', 'NV', 'HI']
repone.loc[repone['State'].isin(target_states), 'Commission %'] = 0.07
repone.loc[~repone['State'].isin(target_states), 'Commission %'] = 0.035

内容的提问来源于stack exchange，提问作者Dusty Bryan