DF.where multiple values

Question

Doing the following :

DF.where(DF['Test']=="a" and DF['Test']=="b")

throw the error :

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

What am I doing wrong ?

Doing :

 DF.where(DF['Test']=="a" & DF['Test']=="b")

returns :

TypeError: Cannot perform 'rand_' with a dtyped [object] array and scalar of type [bool]

Does this answer your question? [Truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all()](https://stackoverflow.com/questions/36921951/truth-value-of-a-series-is-ambiguous-use-a-empty-a-bool-a-item-a-any-o) — Yevhen Kuzmovych, Sep 19 '22 at 13:34
@YevhenKuzmovych thanks but doing this also throw an error but not the same. Editing my post — TourEiffel, Sep 19 '22 at 13:35
Have you copied my solution or just replaced the `and` with `&`. Note the brackets in my line around `(DF['Test']=="a")` and `(DF['Test']=="b")` — Yevhen Kuzmovych, Sep 19 '22 at 13:38
Also, you might want to use "or" (i.e. `|`) otherwise the value needs to be both equal to `'a'` and `'b'` at the same time — Yevhen Kuzmovych, Sep 19 '22 at 13:39
@YevhenKuzmovych thank you v much. It was a bracket issue ! and it was `|` or which was needed — TourEiffel, Sep 19 '22 at 13:41

score 1 · Accepted Answer · edited Sep 19 '22 at 13:43

1

In this case or condition doesn't make a lot of sense, either you want the events of A OR B, never A and B (unless it is a string column). And you are filtering it. In your case I think all you should do is maybe make a isin.

Like the sample

df.where[df['test'].isin(['A','B'])

Also there is an error in your filter case. You are using Python logical constructor when Pandas logical constructor are & | and ~ like this question show peta

Also, there is a bracket issue :

 DF.where((DF['Test']=="a") & (DF['Test']=="b"))

edited Sep 19 '22 at 13:43

TourEiffel

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answered Sep 19 '22 at 13:38

INGl0R1AM0R1

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Hi, upvoted you workaround and also edited your answer by highlighting my mistake. Many thanks, and will accept your answer as soon as i can ! – TourEiffel Sep 19 '22 at 13:44

DF.where multiple values

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