Non-unique dirs in sys.path

[Terry Reedy]

On 1/9/2015 8:14 AM, Gisle Vanem wrote:
> I'm having some trouble understanding why my Python 2.7.9
> has the '%PYTHONHOME%\lib\site-packages' listed multiple
> times.
>
> I cooked up this .bat file to demonstrate the issue:
>    @echo off
>    setlocal
>    set PYTHONPATH=
>    python -c "import sys; [sys.stdout.write('%%s\n' %% p) for (i,p) in
> enumerate(sys.path)]" | sort --ignore-case
>
> which produces:
>
>    f:\Documents and Settings\Gisle
> Vanem\Programdata\Python\Python27\site-packages
>    f:\windows\system32\python27.zip    << !! doesn't exist, but okay.
>    G:\Programfiler\Python27
>    g:\Programfiler\Python27\DLLs
>    g:\Programfiler\Python27\lib
>    g:\Programfiler\Python27\lib\lib-tk
>    g:\Programfiler\Python27\lib\plat-win
>    g:\Programfiler\Python27\lib\site-packages   << !!
>    g:\programfiler\python27\lib\site-packages   << !!
>    ...
>
> Why are these listed twice with different casing? One
> would assume that Python on Win32 would be case-insensitive.
> Some .pth-file to blame here?

To me, this is a bug, as it will, I believe, result in site-packages 
being searched twice before an import fails.

-- 
Terry Jan Reedy