another example:

http://stackoverflow.com/questions/23814368/sorting-pandas-categorical-labels-after-groupby

At the moment bins / buckets are simply strings, so you can't sort them properly.

A=pd.qcut(X['x'], [0,0.25,0.5,0.75,1.0]) In [28]: A[0] Out[28]: '(0.635, 2.4]' In [29]: type(A[0]) Out[29]: str 

The dtype of the Index is object (because these are strings), maybe we could just have these as a subclass of strings where:

def __lt__(self, other): from ast import literal_eval return literal_eval(self) < literal_eval(other) 

Can put together pr if seems reasonable.