Python 使用特定列连接两个 Pandas 数据框
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join two pandas dataframe using a specific column
提问by ahajib
I am new with pandas and I am trying to join two dataframes based on the equality of one specific column. For example suppose that I have the followings:
我是熊猫的新手，我试图根据一个特定列的相等性连接两个数据框。例如，假设我有以下内容：
df1
A B C
1 2 3
2 2 2
df2
A B C
5 6 7
2 8 9
Both dataframes have the same columns and the value of only one column (say A) might be equal. What I want as output is this:
两个数据框具有相同的列，并且只有一列（例如 A）的值可能相等。我想要的输出是这样的：
df3
A B C B C
2 8 9 2 2
The values for column 'A' are unique in both dataframes.
列“A”的值在两个数据框中都是唯一的。
Thanks
谢谢
采纳答案by vk1011
pd.concat([df1.set_index('A'),df2.set_index('A')], axis=1, join='inner')
If you wish to maintain column Aas a non-index, then:
如果您希望将列维护A为非索引，则：
pd.concat([df1.set_index('A'),df2.set_index('A')], axis=1, join='inner').reset_index()
回答by Paul H
Alternatively, you could just do:
或者，你可以这样做：
df3 = df1.merge(df2, on='A', how='inner', suffixes=('_1', '_2'))
And then you can keep track of each value's origin
然后你可以跟踪每个值的来源
