pandas数据替换

1,replace 一次只能替换一个

import pandas as pd

df1 = pd.DataFrame({'temp':['a','b','c','d','a','e','d']})
df2 = df1['temp'].replace('a','ttt')

2,map 替换map中的字符，没写在map中的nan填充\

df1 = pd.DataFrame({'temp':['a','b','c','d','a','e','d']})
df3 = df1['temp'].map({'a':'ttt','d':'qqqqq'})