python - DataFrame filtering

Question

This question already has answers here: question from:https://stackoverflow.com/questions/65894066/dataframe-filtering

Answer 1

It's already been asked, I was just searching the wrong terms.

The short answer is that chained relational operators such as 1 < a < 4 are expanded internally as (1 < a) and (a < 4). and and or cannot be overridden in Python -- see PEP335 and guido's post to the mailing list -- which means numpy can't use chained relational operators as masks. Thus, neither can Pandas.