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Update Pandas df Given String Query

As a result of data introduced by users in the interface I have a string query-like.

query = '(ColA=="7") & (ColB=="3") & (ColC=="alpha") & (ColD=="yu")'

Now I want to update a column of the df based on those conditions, assigning it a variable Z.

I don’t know if it can be done somehow with loc

df.loc[query, 'ColZ'] = Z

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Answer

I got the solution by myself:

df.loc[df.eval(query), 'ColZ'] = Z

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.eval.html

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