[Python-Dev] Python install layout and the PATH on win32

[R. David Murray]

On Wed, 21 Mar 2012 09:09:38 +1100, Mark Hammond <skippy.hammond at gmail.com> wrote:
> On 21/03/2012 5:50 AM, Merlijn van Deen wrote:
> > I asked a question about this on IRC, to which the response was that
> > there were two main reasons to install python in c:\pythonxy:
> >
> > 1 - issues due to spaces ('Program Files') or non-ascii characters in
> > the path ('Fișiere Program' on a Romanian windows). These issues are
> > supposed to be fixed by now (?).
> > 2 - issues due to permissions - installing python / packages in
> > %programfiles% may require administrator rights.
> 
> Apart from personal preference (ie, I prefer the status quo here), the 
> second issue is a bit of a killer.  Even an administrator can not write 
> to Program Files unless they are using an "elevated" process (ie, 
> explicitly use "Run as Administrator" and confirm the prompt.
> 
> This means that any installer wanting to write .py files into the Python 
> install must be elevated, and any Python process wanting to generate 
> .pyc files must also be elevated.  So even if an installer does arrange 
> elevation, unless that installer also compiles all .pyc and .pyo files 
> at install time, Python would fail to generate the .pyc files on first 
> use.  While Python will probably fail silently and still continue to 
> work, it will have a significant performance impact.

So windows requires admin privileges to install to Program Files, but
not to install to '/'?  How novel.  (You can perhaps tell that I'm
not a windoows user).  My understanding, though, is that Python
does make a distinction between a system install of Python and
a per-user one, so I don't think your objection really applies.

That said, there is an open bug in the tracker about the insecurity
of a system install of python (exactly that the files are writable
by anyone).  So that would have to be solved first.  I'd say this
is definitely a separate issue from Van's discussion, and the *only*
reason one might want to tie them together at all is "well, we're
changing the directory layout anyway".

--David