标签：github viewer 左右 数据 pytho div panda mic 合并
Ref:https://nbviewer.jupyter.org/github/pydata/pydata-book/blob/2nd-edition/ch08.ipynb
import pandas as pd
df1 = pd.DataFrame({‘key‘: [‘b‘, ‘b‘, ‘a‘, ‘c‘, ‘a‘, ‘a‘, ‘b‘], ‘data1‘: range(7)}) df2 = pd.DataFrame({‘key‘: [‘a‘, ‘b‘, ‘d‘], ‘data2‘: range(3)}) df1
df2
pd.merge(df1, df2) #不指定on则以两个DataFrame的列名交集做为连接键 ，这里指的是"key"
pd.merge(df1,df2,on = "key")
pd.merge(df1,df2,on = "key",how = "left") #左连接
pd.merge(df1,df2,on = "key",how = "right") #右连接
df2.columns=["key2","data2"] #df2 改名 df2 pd.merge(df1,df2,left_on="key",right_on="key2") ##当左右两个DataFrame的列名不同，指定不同的列明进行merge
#同样可以进行左外连接，右外连接，内链接 pd.merge(df1,df2,left_on="key",right_on="key2",how = "left") pd.merge(df1,df2,left_on="key",right_on="key2",how = "right") pd.merge(df1,df2,left_on="key",right_on="key2",how = "inner")
标签：github viewer 左右 数据 pytho div panda mic 合并
原文地址：https://www.cnblogs.com/yellow-hgy/p/11031060.html
