Expected: pprint the object
Observed: crash with:
set([Traceback (most recent call last):
  File "./test.py", line 7, in <module>
    pp.pprint(myset)
  File "/usr/lib/python2.7/pprint.py", line 117, in pprint
    self._format(object, self._stream, 0, 0, {}, 0)
  File "/usr/lib/python2.7/pprint.py", line 194, in _format
    object = _sorted(object)
  File "/usr/lib/python2.7/pprint.py", line 82, in _sorted
    return sorted(iterable)
TypeError: can only compare to a set


Steps to repro:
#!/usr/bin/python
import pprint
pp = pprint.PrettyPrinter(indent=4)

myset = set(xrange(3))
myset.add(frozenset(xrange(10)))
pp.pprint(myset)