Keep columns after a groupby in an empty dataframe

Question

The dataframe is an empty df after query.when groupby,raise runtime waring,then get another empty dataframe with no columns.How to keep the columns?

df = pd.         


        

Answer 1

You need as_index=False and group_keys=False:

df = df.groupby(["PlatformCategory","Platform","ResClassName"], as_index=False).count()
df

Empty DataFrame
Columns: [PlatformCategory, Platform, ResClassName, Amount]
Index: []

No need to reset your index afterwards.