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

[Matthew Ngaha]

> In a cmd shell, check that 'assoc .py' is "Python.File" and that
> 'ftype Python.File' points to py.exe in your Windows directory, e.g.
> "C:\Windows\py.exe "%1" %*'. If it's wrong, re-install. Or fix it
> manually using assoc and ftype in an elevated cmd shell, which updates
> the local machine registry keys in HKLM\Software\Classes.

i think this is ok, i got these results.
D:\Data\Py\mywork>assoc .py
.py=Python.File

D:\Data\Py\mywork>ftype Python.File
Python.File="D:\Data\Py2.7\python.exe" "%1" %*

> Also, Windows Explorer has an "Open With" dialog that configures
> per-user settings for multiple associations, including a default (i.e.
> the "Always use..." checkbox). These keys are stored in
> HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.py.
> Make sure that UserChoice is set to the Progid "Python.File". You
> should be able to change this using the 'Open With->Choose Default
> Program...' dialog.
>

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.