Error in finding elements of one series which are not in another

Asked Oct 20 '20 at 13:29

Active Oct 20 '20 at 13:29

Viewed 20 times

I am trying to find elements in a series, s1 that are not there in series, s2.

s1 = pd.Series(range(1,6))
s2 = pd.Series(np.array(range(1,6))*2)

pd.Series([item for item in s1 if item not in s2])

I get only the element '5' as the output. Whereas, I should get a series of 1,3,5 as the output.

Similarly, for another example

s1 = pd.Series(range(2,8))
s2 = pd.Series(np.array(range(1,6))*2)

pd.Series([item for item in s1 if item not in s2])

I get only the elements 5,6,7 as outputs. The element 3 isn't received in the output.

Can anyone please guide me on what is happening here?

asked Oct 20 '20 at 13:29

Aniket_b

`s1[~s1.isin(s2)]`? – Quang Hoang Oct 20 '20 at 13:32
Also `np.setdiff1d`. – Quang Hoang Oct 20 '20 at 13:33
1

item in s1 check by the index, you need that @QuangHoang said – ansev Oct 20 '20 at 13:34
Thanks for the suggestion @QuangHoang. I get the right answer by applying your suggestions but I wanted to understand why the list comprehension does not work in this case. – Aniket_b Oct 20 '20 at 13:39
What @ansev said above. `item not in s2` check if `item` is in **the index** of `s2` or not. – Quang Hoang Oct 20 '20 at 13:40
Ok. Got it. Thanks @ansev. Thanks Quang Hoang – Aniket_b Oct 20 '20 at 13:42

0 Answers0