CODEWITHSUNDEEP
pythonpandas
geds133
geds133

Reputation: 1485

Get pandas column where two column values are equal

I want to subset a DataFrame by two columns in different dataframes if the values in the columns are the same. Here is an example of df1 and df2:

df1
    A         
0   apple
1   pear
2   orange
3   apple

df2
    B
0   apple
1   orange
2   orange
3   pear

I would like the output to be a subsetted df1 based upon the df2 column:

    A   
0   apple
2   orange

I tried df1 = df1[df1.A == df2.B] but get the following error:

ValueError: Can only compare identically-labeled Series objects

I do not want to rename the column in either.

What is the best way to do this? Thanks

Upvotes: 1

Views: 38

Answers (1)

jezrael
jezrael

Reputation: 862601

If need compare index values with both columns create Multiindex and use Index.isin:

df = df1[df1.set_index('A', append=True).index.isin(df2.set_index('B', append=True).index)]
print (df)
        A
0   apple
2  orange

Upvotes: 2

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