Python Proper way to override equal to and hash

override_eq.py

# http://stackoverflow.com/questions/390250/elegant-ways-to-support-equivalence-equality-in-python-classes
# http://stackoverflow.com/questions/4352244/python-implementing-ne-operator-based-on-eq/30676267#30676267

class Test1(object):
    """
    Proper way to override equality
    
    """
    def __init__(self, str1, str2, num1):
        self.str1 = str1
        self.str2 = str2
        self.num1 = num1

    def __eq__(self, other):
        return isinstance(other, self.__class__) and self.__dict__ == other.__dict__
    
    # If you dont define ne when overriding eq you get inconsisten behaviour
    def __ne__(self, other): 
        return not self == other 

    def __hash__(self):
        data = [
            self.str1,
            self.num1,
            self.__class__
        ]
        return hash("{},{},{}".format(*sorted(data)))
    
k1 = Test1("1","11",1)
k2 = Test1("1","11",1)
print k1 == k2 # True 
print k1 != k2 #  False but will evaluvate to True if you comment out override the ne part!!