[Tutor] how can i use python 2 alongside 3?

[eryksun]

On Thu, Jan 24, 2013 at 5:39 PM, Matthew Ngaha <chigga101 at gmail.com> wrote:
>
> D:\Data\Py\mywork>ftype Python.File
> Python.File="D:\Data\Py2.7\python.exe" "%1" %*

That's the file class created by the 2.7 installer in the HKLM (local
machine) Software hive.

    Overview of the Windows Registry:
    http://en.wikipedia.org/wiki/Windows_Registry

The cmd shell's assoc/ftype use HKLM classes. However, I see now that
the standalone launcher configures HKCU (current user) classes. These
take precedence over HKLM classes, so assoc and ftype aren't showing
the complete picture.

HKCR (classes root) is the merged view. The following shows the
current default command to open a Python.File:

    reg query HKCR\Python.File\shell\open\command

> i dont quit understand when you say UserChoice is set to the Progid
> "Python.File"? what is Progid? i cant seem to locate that path
> HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.py.

    reg query HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.py\UserChoice

If you've selected a default using the "Open With" dialog, there
should be a 'Progid' set to, for example, Python.File. Modify this
using the Explorer "Open With"/"Choose Default Program..." dialog. I
mention this because installers don't generally modify this key. It's
set manually by the user -- possibly to an editor or a specific Python
executable instead of the configured Python.File class.