Pandas 'unstack' returns a Series instead of a Dataframe?
What causes Pandas 'unstack' to output a series instead of a Dataframe?

import pandas as pd;

events = pd.DataFrame.from_csv('/Users/davidlaxer/gdelt/events/20150613.export.CSV', sep='\t', index_col='GLOBALEVENTID')

e = events.unstack()
type(e)

Out[129]:
pandas.core.series.Series
