== versus is operators and type()

[Jeremy Hylton]

> As an example, are the two expressions bellow totally equivalent?
>
> type(arg) is type(0) or type(arg) is type(0.0)
>
> type(arg) in (type(0), type(0.0))

Yes, in general.  All of the standard Python types, including classes,
define equality using object identity.  It's never the case that there can
be two type objects that are equal but have different addresses.  So the
behavior of == and is operations are the same.