How to avoid UserWarning: Boolean Series key will be reindexed to match DataFrame index?

Question

My input:

df.query('date == 2009')[df['id'] == 35988].index[0]

The error raised:

C:\Anaconda\lib\site-packages\ipykernel_launcher.py:1: UserWarning: Boolean Series key will be reindexed to match DataFrame index. "Entry point for launching an IPython kernel.

The output:

How to avoid an error, keeping given output?

Possible duplicate of https://stackoverflow.com/questions/51055788/userwarning-boolean-series-key-will-be-reindexed-to-match-dataframe-index — , Feb 12 '19 at 15:18

score 1 · Answer 1 · answered Feb 10 '19 at 22:16

1

Without example data, I can't test these potential solutions, but maybe one or both will work for you.

Option 1: include both conditions in DatFrame.query:

df.query('date == 2009 & id == 35988').index[0]

Option 2: reverse the order of the two queries with something like this:

df[df['id'] == 35988].query('date == 2009').index[0]

answered Feb 10 '19 at 22:16

Peter Leimbigler

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Thank you, Peter. I already found the second option... let me check the first one )) – AlexR Feb 10 '19 at 22:22
FIrst one is not works, due different data types in 'date' and 'id' – AlexR Feb 10 '19 at 22:26
Interesting. What are the data types of `date` and `id`? Not both integers? – Peter Leimbigler Feb 10 '19 at 22:27
date - int, id - int – AlexR Feb 10 '19 at 22:29
TypeError: unsupported operand type(s) for &: 'str' and 'str' – AlexR Feb 10 '19 at 22:40
interesting... both don't work in 'for loop', where values are changed to variables.. trying to find a way to use .loc instead .query – AlexR Feb 10 '19 at 23:08

How to avoid UserWarning: Boolean Series key will be reindexed to match DataFrame index?

1 Answers1