Apply Functions to Inner Dict in Groupby
I have a problem where I need to use the value of the column by which a grouped dataframe is transformed.

The code is a complicated case of the following, where column are labelled by instances of a Python class:

```
# group by a value in the column instance
per_column = results.groupby(lambda x : x.value, 1)
for k, v in per_column:
  v = v.apply(function(k, v))
```

Basically, a transformation for a group  needs to consider both the value of the index by which the frame is grouped and the dataframe itself.
This works, but the grouped object's values aren't actually changed, so I have to load them into a new dictionary.
Is this possible creating a new dictionary (that I then can't really converted into a grouped object)?
