source: utilitiespy/test/tools/safehashtest.py

import unittest
from tudelft.utilities.tools.safehash import safehash


class A:
        def __hash__(self):
                return 1
        
class B(A):
        def __hash__(self):
                return safehash(super())+1


class SafeHashTest(unittest.TestCase):

        
        def tests(self):
                lst=[1,2,3]
                safehash(lst)
                safehash({'a':1})
                safehash( set(lst))
                safehash({'a':set(lst)})
                
                h1= safehash({'a':1})
                h2= safehash({'a':2})
                self.assertNotEqual(h1,h2)
                
                h1= safehash({'a':1,'b':2})
                h2= safehash({'b':2,'a':1})
                self.assertEqual(h1,h2)

                self.assertEqual(2, safehash(B()))

                # you can a set in a set...
                #safehash(set([set(lst)]))