__del__ and reference count problem

[flupke]

Hi,
i'm starting work and a simple database layer and wanted to use the 
__del__ to open and close a connection. However, i get an erro when 
executing this script:

class Table:
    refcount = 0
    def __init__(self, name):
        self.name = name
        print "table %s " % repr(self)
        Table.refcount += 1
        print "refcount = %s" % str(Table.refcount)
    def __del__(self):
        Table.refcount -= 1
        if (Table.refcount == 0):
            print "Last table standing"
        else:
            print "There is/are still %d table(s) left." % Table.refcount
    def __getitem__(self,item):
        return "not implemented"
    def howMany(self):
        if (Table.refcount == 1):
            print "Only 1 table"
        else:
            print "There are %d tables active." % Table.refcount
if __name__ == '__main__':
    suppliera = Table("suppliers")
    supplierb = Table("suppliers")
    print "Supplier returned from a %s: %s" % (1, suppliera[1])
    print "Supplier returned from b %s: %s" % (2, supplierb[2])
    suppliera.howMany()
    supplierb.howMany()
This produces the following output and error:
table <__main__.Table instance at 0x008D5C10>
refcount = 1
table <__main__.Table instance at 0x008D5C38>
refcount = 2
Supplier returned from a 1: not implemented
Supplier returned from b 2: not implemented
There are 2 tables active.
There are 2 tables active.
Exception exceptions.AttributeError: "'NoneType' object has no attribute 
'refcount'" in <bound method Table.__del__ of <__main__.Table instance 
at 0x008D5C10>> ignored
Exception exceptions.AttributeError: "'NoneType' object has no attribute 
'refcount'" in <bound method Table.__del__ of <__main__.Table instance 
at 0x008D5C38>> ignored

What am i doing wrong?
Thanks
Benedict
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