How to install Python package from source on Windows

[Deborah Swanson]

Chris Angelico wrote, on Monday, May 15, 2017 11:22 AM
> 
> On Tue, May 16, 2017 at 4:12 AM, Deborah Swanson 
> <python at deborahswanson.net> wrote:
> > It continues to amaze me that Anaconda and Python.org, probably the 
> > two biggest distributors of official Python builds, are now relying
on 
> > Visual C++. Why can't Python developers write the entire setup and 
> > installation code in Python? Surely Python has the required 
> > functionality, and it seems more than a little demeaning for Python
to 
> > be using Visual C++ as a crutch.
> 
> Are you suggesting that a C compiler should be written in 
> Python? Because you're dealing with an extension library. 
> It's not written in pure Python. That's why it needs a C 
> compiler. While it is certainly possible to write a C 
> compiler in Python, it is unlikely to outperform the existing 
> popular compilers (gcc, clang, msvc, etc), which have had 
> many years of expertise poured into them.

I don't know much about extensions yet, but I think I can see what
you're saying. It probably is a shortcut for volunteer developers to use
existing C/C++ code where they can, rather than writing all of it from
scratch in Python.

But I'm a little more mystified that official Python builds are leaning
on Visual C++ (and that's what the crutch comment was primarily aimed
at). Perhaps they're just as resource needy as the extension developers
are and new requirements have come up as Python 3 progresses that they
don't already have Python build and installation tools written and
tested for. I'd be willing to step into that void when my Python skills
are equal to the task (and my health permitting, of course). But that
would be years from now, and maybe someone else will step up before
then. I'm really thinking that build has languished far behind the rest
of the language's development for way too long.

> None of this applies if you are actually depending on a pure 
> Python module, which *can* be installed without a C compiler. 
> Visual C++ is not a crutch but a critical part of the build process.
> 
> ChrisA

I'll still think of it as a crutch for official Python builds, but I can
see your point for extension developers. 

Maybe I have more pride in the Python language than is right and proper,
but I do think it would be worth the relatively small investment to make
and start growing Python's own build and installation tools asap. Python
will be the reigning Queen of coding languages someday. Certainly seems
like she should have all her own working parts and be beholden to no
one. ;)

Microsoft saw the need for build and installation teams very early on,
and now everyone depends on what they made. 

And yes, Windows and all Microsoft software from thence forward was
primarily made with C/C++, because MSDOS was appallingly incapable of
meeting the challenge and that's all they had before Windows. 

Python has a lot more than MSDOS ever dreamed of, and that's what seems
demeaning to me that Python is piggybacking on a lesser language,
because their need to do so is so infinitesimally less than Microsoft's
need was to move on from MSDOS. And I think the day is coming that
Microsoft will be too much of a dinosaur (like IBM has become) to
continue meeting the needs of evolving languages. Better to get going on
our own tools, the sooner the better, in my opinion.

Deborah