It would be really nice to have the ability to put pandas dataframes into sklearn pipelines, and to have equivalent pandas dataframes returned afterwards. I think that this module would be the place for that - probably all that would be required is a .inverse_transform method on the DataFrameMapper.

Would something like this be wanted in this module? I can make a pull request, if so.

Before I do, why is all the code in __init__.py? Seems like it'll get hard to maintain after a while...