Pairwise set intersection of 2 Pandas Series of 2 different Pandas dataframes in order without merging

Question

I have 2 Pandas dataframe and I want to find the length of the intersection of 2 columns in order. For example:

    df1 = 

 a           b
 a1          b1
 a2          b2
 a3          b3

  df2 =
 a           b
 a1          b1
 a4          b4
 a2          b4



 Answer: 1  only 1 pair is in common (a1.  b1)

For 1 column, I can simply write:

 set(df1.a).intersection(set(df2.a))

How to do this for 2 columns without merging the 2 data frames and is it possible?

EDIT: I want it without merging

Ok, I see. I also upvoted the answer. It is no problem. – learner Sep 18 '20 at 21:06 — learner, Sep 18 '20 at 21:06

score 2 · Answer 1 · answered Sep 18 '20 at 16:53

2

You can use merge:

df1.merge(df2, on=['a','b'])

Output:

    a   b
0  a1  b1

answered Sep 18 '20 at 16:53

Quang Hoang

146,074
10
56
74

Pairwise set intersection of 2 Pandas Series of 2 different Pandas dataframes in order without merging

1 Answers1