FWIW you could give the most information (the types of the repeated tools) using something like this:
```
In [8]: foo = ["a", "b", 1, 2.2]

In [9]:  for typ, grp in itertools.groupby(sorted(type(i) for i in foo)):
   ...:     if len(list(grp)) > 1: print typ
   ...:    
<type 'str'>
```