one line if statement, ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all()

Question

I am getting this error when I try to add a column to my pandas dataset based on the following conditions.

df['name'] = (1 if (df['name2'] > 0) and (df['name3'] == 0) else 0)

I would really appreciate some help with this, I am very new to python.

Thanks.

Does [this](https://stackoverflow.com/questions/36921951/truth-value-of-a-series-is-ambiguous-use-a-empty-a-bool-a-item-a-any-o) solve your question? — Jan Stránský, Aug 25 '20 at 17:54
@anona Yes because you then run into a similar problem with `if` — alani, Aug 25 '20 at 17:59
@superbrain It's mentioned in the accepted answer in the question that Jan linked. — alani, Aug 25 '20 at 18:09
Anyway, the point is that both the `and` and the `if` will try to assign truth values to an entire array, and that you need to use equivalents that will do element-by-element operations. — alani, Aug 25 '20 at 18:12

NYC Coder · Answer 1 · 2020-08-25T17:57:13.697

0

You can use numpy.where:

df['name'] = np.where((df['name2'] > 0) & (df['name3'] == 0), 1, 0)

edited Aug 25 '20 at 17:57

answered Aug 25 '20 at 17:56

NYC Coder

But you are still using `and`. You need `&`. – alani Aug 25 '20 at 17:56
This gave the same error, then I changed the 'and' to '&' and it worked, thanks – anona Aug 25 '20 at 18:01
Ok cool, you can mark this as the answer if it worked. – NYC Coder Aug 25 '20 at 18:03

1 Answers1