Is the following code returning a generator expression?

[Gribouillis]

Why are you doing "if x is e or x == e"? Can you ever have the check for identity be True when the check for equality is False?

I think @quazirfan was only quoting the Python documentation at the point where it explains the behavior of the in operator in common containers. Note than in the test x is e or x == e, the == operator is only evaluated if x is not e. I think the documentation means that pointer equality is tried before anything else.

By default, object implements __eq__() by using is, returning NotImplemented in the case of a false comparison: True if x is y else NotImplemented. For __ne__(), by default it delegates to __eq__() and inverts the result unless it is NotImplemented. There are no other implied relationships among the comparison operators or default implementations

Am I correct to guess there is no difference

There is no difference at all.