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Date: Wed, 12 Feb 2014 12:05:49 +1100
Subject: Re: Fun with function argument counts
From: Chris Angelico <rosuav@gmail.com>
Cc: "python-list@python.org" <python-list@python.org>
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On Wed, Feb 12, 2014 at 11:34 AM, Travis Griggs <travisgriggs@gmail.com> wr=
ote:
> 1) I did not want to try load all modules at once into my environment. I =
suspect that would create problems. Using os.fork() to isolate the load/ana=
lysis of each module was a handy way to deal with that. The trick of using =
if pid: branch to split of the flow of execution was cool. Maybe it=E2=80=
=99s the wrong tool for the job and I missed an obvious one, but I thought =
it was kinda clever.
>

That's the normal way to use fork() in any environment. The standard C
idiom is to call fork(), and then test for *three* possibilities: 0
means you're in the child, >0 means you're in the parent, and <0 means
you're still in the parent, and forking failed. Python simplifies that
a bit by raising an error if something goes wrong, so you can simply:

if os.fork():
    # Parent continues
else:
    # Child process

> 2) Using cpython, a lot of the core library can=E2=80=99t be reflected on

That's being improved as of 3.4, thanks to Argument Clinic. Though the
whole stdlib might not be converted, so you might have to wait for
3.5.

> 4) optional arguments were an interesting dillema. I chose to reduce the =
argument count of a signature by the number of default arguments. Since the=
y are essentially optional. So the stats there have a bias to the =E2=80=9C=
minimal=E2=80=9D call signature.
>

That's one way to look at it. That tells you what can be called with
no args. But it's not always a fair look at the function's usefulness;
maybe with no arguments, it always returns a constant value:

>>> bool()
False

The bool function (really the type/constructor) is much more useful
with an argument, but it's technically callable without.

> 6) Who writes a function with 19 mandatory arguments anyway????  subproce=
ss._execute_child() and distutils.cygwincompiler._execute_child()

Hmm. Those are internal functions (leading underscore). Might be
fairer to remove those from consideration.

ChrisA