On 20/06/17, Toshio Kuratomi wrote:
On Tue, Jun 20, 2017 at 6:06 AM, Kushal Das <mail(a)kushaldas.in>
wrote:
> Type annotations or type hints are purely for
> external type checking tools, they do not affect the Python interpreter
> anyway.
Note that this statement is incorrect. Code like this:
https://docs.python.org/3/library/typing.html#user-defined-generic-types
where inheritance of a class from the typing module is used affects
running code. Mark Shannon gave a talk at the pycon language summit
and plead for the typing module to divorce type checking from
inheritance and pointed out that the implementation slows down
runtime. He further pointed out that using inheritance for type
information like this was not a proper fit; that sometimes the class
inherited from should not have anything to do with the type
information.
Thanks for pointing this one out, I somehow missed both of Mark's
talks
in the language summit. Now, I went back and read the report on his
talk[1]. I hope the core-denels will come up with solutions to the
problem he pointed up in proper time.
Thanks once again for pointing this one.
[1]
https://lwn.net/Articles/724639/
Kushal
--
Fedora Cloud Engineer
CPython Core Developer
https://kushaldas.in
https://dgplug.org