Pandas: select rows where two columns are different

Question

Suppose I have a dataframe as below

Now I want the rows where column a and b are not same. So the expected outpu is

a  b  c 
0  2  74
1  4  44

How can I do this?

possible duplicate (generalisation): https://stackoverflow.com/questions/17071871/select-rows-from-a-dataframe-based-on-values-in-a-column-in-pandas — jpp, Feb 12 '18 at 16:36

score 24 · Accepted Answer · answered Feb 12 '18 at 16:35

24

I am a fan of readability, use query:

df.query('a != b')

Output:

   a  b   c
1  0  2  74
3  1  4  44

answered Feb 12 '18 at 16:35

Scott Boston

score 7 · Answer 2 · answered Feb 12 '18 at 16:32

7

Try this:

df.loc[df['a'] != df['b']]

answered Feb 12 '18 at 16:32

jpp

score 3 · Answer 3 · answered Feb 12 '18 at 16:32

3

By using nunique

df.loc[df[['a','b']].nunique(1)>1]
Out[335]: 
   a  b   c
1  0  2  74
3  1  4  44

answered Feb 12 '18 at 16:32

BENY

score 1 · Answer 4 · answered Feb 12 '18 at 16:33

1

Just use:

df.loc[df['a']!=df['b']]

answered Feb 12 '18 at 16:33

zipa

4 Answers4