I'm doing a group by in a pandas dataframe, how can I change the name of the aggregate column after the group by?
df.groupby(['open_year','open_month','source']).size().reset_index()
it creates a dataframe with the following columns
open_year, open_month, CREATED_BY_REVISED, 0
I', trying to rename the last colum(0) but it doesn't work
x.rename({'0':'xyz'})