[Python-ideas] PEP: Distributing a Subset of the Standard Library

[Ethan Furman]

On 11/28/2016 08:35 AM, Random832 wrote:
> On Mon, Nov 28, 2016, at 10:51, Tomas Orsava wrote:

>> Could some Windows user please check if compiling Python with the
>> current reference implementation [2] of this PEP indeed generates a
>> `curses.missing.py` file among the stdlib files? If so, we might
>> consider skipping the generation of the .missing.py file for the curses
>> module on Windows.
>
> "Skip it for curses on Windows" doesn't seem like an acceptable
> solution, because tomorrow there could be another module, on another
> platform, that needs a similar fix. I think it'd be better to fix the
> logic. Searching the whole path for whatever.py before searching for
> whatever.missing.py makes sense to me [...]

Agreed.

> Honestly, though, I'm not sure of the need for the PEP in general.
> "However, there is as of yet no standardized way of dealing with
> importing a missing standard library module." is simply not true. The
> standardized way of dealing with it is that the import statement will
> raise an ImportError exception. Why exactly is that not good enough?

Because it is unfriendly.  Helpful error messages are a great tool to both beginner and seasoned programmers.

> A distribution could, for example, include an excepthook in site.py that
> prints an informative error message when an ImportError is unhandled for
> a list of modules that it knows about.  [...]

As you say above, that list will fall out of date.  Better to have a standard method that is easily implemented.

--
~Ethan~