Sorting things into bins

[Sue Giller]

Is there a quick and simple way to sort a set of values (strings in this 
case) into a set of bins, based on a subset of the characters in the 
string?

This is a very simplified, small version of what I want to do, but if I 
can solve this example, I think I can expand it to fix my problem.  All 
strings would be same length.  These strings are contained in a list. 
For example,  a set of strings that look like numbers.   There is a 
pattern to the strings, as they represent date:time values and they 
can't easily be converted to a number.
['0101', '0102', '0103', '0201', '0202', '0203]

I might want to sort them into two bins which I will define from the list 
of string (bins are all values for first 2 chars in the strings):
01, 02, => then 01 contains '0101', '0102', '0103', and 02 contains 
0201, 0202 and 0203

or I might want to sort them into three bins (bins are all values for 
second 2 chars in the strings):
01, 02, 03 =>  then 01 contains 0101 and 0201, and 02 contains 
0102, 0202, and 03 contains 0103 and 0203

The real bins will be built from a longer string than 2 chars.

For some reason, I think this should have an elegant solution in 
python, but I am too much a newbie to see it. 

Any suggestions?  Thanks