[Python-3000] callable()

[Guido van Rossum]

So how about we change callable() and add hashable(), iterable() and
whatever else makes sense so that these all become like this:

  def callable(x):
    return getattr(x, "__call__", None) is not None

This way classes can explicitly declare that they aren't callable,
hashable, iterable etc. by setting the corresponding attribute to
None.

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)