[Python-Dev] Type hints -- a mediocre programmer's reaction

[Paul Sokolovsky]

Hello,

On Thu, 23 Apr 2015 09:15:44 -0400
Daniel Holth <dholth at gmail.com> wrote:

[]

> >> Also ask why no one used type specifier, they are possible since
> >> Python 3.0 ?
> >> Because it is the wrong way for Python.
> >
> > That's an example of how perceptions differ. In my list, everyone(*)
> > uses them - MyPy, MicroPython, etc. Even more should use them (any
> > JIT module, which are many), but sit in the bushes, waiting for a
> > kick, like PEP484 provides.
> 
> It's OK that type hints are only to assist the programmer.

Yes, it's OK to have a situation where type hints assist only a
programmer. It's not OK to think that type hints may be useful only for
programmer, instead of bunch more purposes, several of which
were already shown in the long previous discussion.

> PyPy's FAQ
> has an explanation of why type hints are not for performance.
> http://pypy.readthedocs.org/en/latest/faq.html#would-type-annotations-help-pypy-s-performance

You probably intended to write "why type hints are not for *PyPy's*
performance". There're many other language implementations and modules
for which it may be useful, please don't limit your imagination by a
single case.

And speaking of PyPy, it really should think how to improve its
performance - not of generated programs, but of generation itself. If
compilation of a trivial program on a pumpy hardware takes 5 minutes
and gigabytes of RAM and diskspace, few people will use it for other
purposes beyond curiosity. There's something very un-Pythonic in
waiting 5 mins just to run 10-line script. Type hints can help here
too ;-) (by not wasting resources propagating types thru the same old
standard library for example).


-- 
Best regards,
 Paul                          mailto:pmiscml at gmail.com