Extracting specific selected columns to new DataFrame as a copy

Question

I have a pandas DataFrame with 4 columns and I want to create a new DataFrame that only has three of the columns. This question is similar

Answer 1

As far as I can tell, you don't necessarily need to specify the axis when using the filter function.

new = old.filter(['A','B','D'])

returns the same dataframe as

new = old.filter(['A','B','D'], axis=1)