Generic proxy (that proxies methods like __iter__)

[D HANNEY]

>>> def show(opened):
...         with opened as file:
...                 for line in file:
...                         print line.strip()
...

>>> show(open("test.txt"))
blah1
blah2
blah3


#
# Good! I wonder if I can do that with StringIO ...
#


>>> import StringIO
>>> show(StringIO.StringIO("blah1\nblah2\nblah3\n"))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in show
AttributeError: StringIO instance has no attribute '__exit__'

#
# Oh dear ... I'll need to proxy it ...
#


>>> class IterNoGuardProxy(object):
...         def __init__(self, t):
...                 self.t = t
...         def __enter__(self):
...                 return self
...         def __exit__(self, type, value, traceback):
...                 return False
...         def __iter__(self):
...                 return self.t.__iter__()
...
>>> show(IterNoGuardProxy(StringIO.StringIO("blah1\nblah2\nblah3\n")))
blah1
blah2
blah3
>>>


#
# Great! That works well. Now I wonder if I can do it generically
# in a way that can proxy for ALL methods (including, but not limited
to, __iter__)
#


>>> class NoGuardProxy(object):
...         def __init__(self, t):
...                 self.t = t
...         def __enter__(self):
...                 return self
...         def __exit__(self, type, value, traceback):
...                 return False
...         def __getattr__(self):
...                 return self.t.__getattr__(self)
...
>>> show(NoGuardProxy(StringIO.StringIO("blah1\nblah2\nblah3\n")))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in show
TypeError: 'NoGuardProxy' object is not iterable

#
# Now I'm stuck.
# Can anyone help?
#