#!/usr/bin/env python3
# -*- coding: utf-8 -*-


# A mapping class only implementing __getitem__
class WithoutSetItem:
    def __getitem__(self, key):
        return "foo"

# A mapping class also implementing __setitem__
class WithSetItem:
    def __getitem__(self, key):
        return "foo"
    def __setitem__(self, key, val):
        return


# Trying to use del on an item of the calss without __setitem__
# results in "TypeError: 'WithoutSetItem' object doesn't support item deletion"
wo = WithoutSetItem()
try:
    del wo[0]
except Exception as e:
    print("WithoutSetItem =>", repr(e))


# Trying to use del on an item of the calss with __setitem__
# results in "AttributeError: __delitem__"
w = WithSetItem()
try:
    del w[0]
except Exception as e:
    print("WithSetItem =>", repr(e))