In the dataframe below, I would like to eliminate the duplicate cid
values so the output from df.groupby('date').cid.size()
matches the output from df.groupby('date').cid.nunique()
.
I have looked at this post but it does not seem to have a solid solution to the problem.
df = pd.read_csv('https://raw.githubusercontent.com/108michael/ms_thesis/master/crsp.dime.mpl.df')
df.groupby('date').cid.size()
date
2005 7
2006 237
2007 3610
2008 1318
2009 2664
2010 997
2011 6390
2012 2904
2013 7875
2014 3979
df.groupby('date').cid.nunique()
date
2005 3
2006 10
2007 227
2008 52
2009 142
2010 57
2011 219
2012 99
2013 238
2014 146
Name: cid, dtype: int64
Things I tried:
df.groupby([df['date']]).drop_duplicates(cols='cid')
gives this error: AttributeError: Cannot access callable attribute 'drop_duplicates' of 'DataFrameGroupBy' objects, try using the 'apply' method
df.groupby(('date').drop_duplicates('cid'))
gives this error: AttributeError: 'str' object has no attribute 'drop_duplicates'
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