import pandas as pd import numpy as np df1=pd.DataFrame({'key':['b','b','a','c','a','a','b'],'data1':range(7)}) df2=pd.DataFrame({'key':['a','b','d'], 'data2':range(3)}) pd.merge(df1,df2) #没有指明联结的建,会将重叠列的列名当作键. pd.merge(df1,df2,on='key').sort_values(