Filtering pandas dataframe based on attribute of object in a column

Question

This is something that I can do with a roundabout measure, but I'm wondering if there's something offered by Pandas that makes this possible which might be missing.

So I have a column, "objects", which contains objects that have attributes. One of those attributes is something called "key". I'm trying to filter my dataframe to only include objects whose key belongs in a certain list:

df2 = df[df["object"].key.isin(list_of_keys)]

The error this returns is AttributeError: 'Series' object has no attribute 'key'

I tried something like this too, but it didn't work:

df2 = df[df["object"].map(lambda x: x.key).isin(list_of_keys)]

This returns an even more inscrutable error: TypeError: ufunc 'bitwise_and' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''

Answer 1

Try comparing directly within the lambda function:

df2 = df[df["object"].map(lambda x: x.key in list_of_keys)]