Not quite sure if this is intentional behavior, but noticed that df.copy() accepts argument deep and series.copy() does not. > > > from pandas import Series, DataFrame > > > s=Series([1,2,3]) > > > df=DataFrame(s) > > > df.copy(deep=True) > > > 0 > > > 0 1 > > > 1 2 > > > 2 3 > > > s.copy(deep=True) > > > Traceback (most recent call last): > > > File "<stdin>", line 1, in <module> > > > TypeError: copy() got an unexpected keyword argument 'deep'