def equals(a, b):
    if isinstance(a, pony.orm.core.Entity):
        return type(a) == type(b) and a.get_pk() == b.get_pk()
    return a == b

with db_session:
    a = Customer[1]
with db_session:
    b = Customer[1]
print(a is b, a == b, equals(a, b))    # False, False, True