iteritems behaves strangely!

itertest.py

#!/usr/bin/env python

from collections import MutableMapping

class Itertest(MutableMapping):
  
	def __init__(self):
		self.underlying = {}

	def __getitem__(self, key):
		print "Getting %s" % key
		return self.underlying[key]

	def __setitem__(self, key, value):
		print "Setting %s to %s" % (key, value)
		self.underlying[key]=value

	def __delitem__(self, key):
		del self.underlying[key]

	def __len__(self):
		return len(self.underlying)

	def __iter__(self):
		return iter(self.underlying)

x = Itertest()
x['a'] = 3
x['b'] = 4
x['k'] = 'cd'

print "Regular iteration"
for key in x:
	print key

print 'iteritems:'
for key, val in x.iteritems():
	print key, val

print 'items:'
for key, val in x.items():
	print key, val