CODEWITHSUNDEEP
pythonpandasdataframe
Arcanesaw
Arcanesaw

Reputation: 39

Merge dataframes but without intersecting values from the right dataframe

I have two dataframes A and B

A = pd.DataFrame({'a'=[1,2,3,4,5], 'b'=[11,22,33,44,55]})
B = pd.DataFrame({'a'=[7,2,3,4,9], 'b'=[123,234,456,789,1122]})

I want to merge B and A such that I don't want the common values in column 'a' in A and B from B, only non-intersecting values from B in column 'a' should be taken. The final dataframe should look like

a b
1 11
2 22
3 33
4 44
5 55
7 123
9 1122

Upvotes: 1

Views: 168

Answers (1)

Quang Hoang
Quang Hoang

Reputation: 150825

If a is unique-valued in both A and B (some sort of unique ID for example), you can try with concat and drop_duplicates:

pd.concat([A,B]).drop_duplicates('a')

Output:

   a     b
0  1    11
1  2    22
2  3    33
3  4    44
4  5    55
0  7   123
4  9  1122

In the general case, use isin to check for existence of B['a'] in A['a']:

pd.concat([A,B[~B['a'].isin(A['a'])])

Upvotes: 2

Related Questions