Description
Blocker for 0.11.1. This got broken sometime between 0.11.0 and master; I haven't had time to bisect yet. Essentially, write a mixed type DataFrame and a groupby function that extracts a row. This used to do type inference and convert object back to numeric in the columns of the resulting DataFrame. Didn't have a test so I don't blame anyone for breaking it by accident =)
In [151]: cafdata.dtypes
Out[151]:
id int64
food object
fgroup object
nutrient object
ngroup object
units object
value float64
dtype: object
In [152]:
def max_value(group):
return group.ix[group['value'].idxmax()]
max_value(cafdata)
Out[152]:
id 14366
food Tea, instant, unsweetened, powder
fgroup Beverages
nutrient Caffeine
ngroup Other
units mg
value 3680
Name: 336702, dtype: object
In [153]: cafdata.groupby('fgroup').apply(max_value).dtypes
Out[153]:
id object
food object
fgroup object
nutrient object
ngroup object
units object
value object
dtype: object