Attribute Error: Rich Comparison Configuration

Question

I have a Point class with x and y attributes. I would like to get a False comparison of a Point object with any other type of object. For example, Point(0, 1) == None does not work:

 AttributeError: 'NoneType' object has no attribute 'x' 

Grade:

 class Point(): def __init__(self, x, y): self.x = x self.y = y def __eq__(self, other): return self.x == other.x and self.y == other.y def __ne__(self, other): return not self.__eq__(other) 

How do I configure __eq__ to get False compared to any other type of object?

Answer 1

 def __eq__(self, other): if not isinstance(other, Point): return False try: return self.x == other.x and self.y == other.y except AttributeError: return False 

First check the type and return False if it is not a Point instance. We do this if they compare another type that has the x or y attribute, but not necessarily the same context.

The second is catching an attribute error, just in case someone subclasses Point and removes the attribute or changes the point in some way.

Answer 2

I would see if another object would act like a Point object instead of rejecting all non Point objects:

 def __eq__(self, other): try: return self.x == other.x and self.y == other.y except AttributeError: return False 

So Point(1, 1) == Vector(1, 1) if you use coordinate vectors.

Answer 3

Try the following:

 def __eq__(self, other): return isinstance(other, Point) and self.x == other.x and self.y == other.y