what about
if foo in (Sometype,):
...compared to
if foo is Sometype:
...is
in more like
is or more like
==? in this usage i want to determine if foo's value is the type itself ... or not. it's about how
in works.
The Documentation Wrote:For container types such as list, tuple, set, frozenset, dict, or collections.deque, the expression x in y is equivalent to any(x is e or x == e for e in y).
See
here. Thus, if
is fails to be true,
== is attempted.
That said, objects' equality
== defaults to
is. As types are usually instances of the
type type, I would guess that equality for types is the same as
is by default, unless you define metaclasses that override
__eq__ (which I don't think I have ever done), so it should generally work in this case.
Now if by any chance
foo happens not to be a type at run time, there could be a call to
foo.__eq__(Sometype) which consequences we do not know. With the
is operator, nothing unexpected can happen.
foo could be a non-type in which case i want false even if it is an object of that type or any other. it could be None.