BUG AttributeError: 'DataFrameGroupBy' object has no ...
https://github.com/pandas-dev/pandas/issues/1164018.11.2015 · I guess it will be clearer with an example. First, let's prepare the dataframe: In [2]: df = pd.DataFrame(columns=['a','b','c','d'], data=[[1,'b1','c1',3], [1,'b2 ...