"""Container function overloading

This class illustrates the special member functions use to overload
operators that work on container classes.

See http://docs.python.org/ref/sequence-types.html for more details.

>>> c = abscontainer.AbstractContainer()
>>> len(c)
Called len(container)
0
>>> c[2]
Called container[2]
>>> c['Paris'] = 'France'
Called container[Paris] = France
>>> del c[15.5]
Called del container[15.5]
>>> [x for x in c]
Called for x in container
[None]
>>> 'zed' in c
Called zed in container
False
>>> 
"""

class AbstractContainer(object):
    def __repr__(self):
        return "container"
        
    def __len__(self):
        print "Called len(%s)" % self
        return 0

    def __getitem__(self, key):
        print "Called %s[%s]" % (self, key)
        return None

    def __setitem__(self, key, value):
        print "Called %s[%s] = %s" % (self, key, value)

    def __delitem__(self, key):
        print "Called del %s[%s]" % (self, key)

    def __iter__(self):
        print "Called for x in %s" % self
        yield None

    def __contains__(self, item):
        print "Called %s in %s" % (item, self)
        return False