Do 2.2 and 2.1.1coexist well?

David C. Ullrich ullrich at math.okstate.edu
Mon Dec 3 13:05:13 EST 2001


On Sun, 2 Dec 2001 03:57:12 -0500, "Tim Peters" <tim.one at home.com>
wrote:

>[Ron Turner]
>> Is it safe to install and run both 2.2 and 2.1.1 on the same machine? I
>> realize that the directory structures are nicely separated, but I am not
>> certain whether there may be DLLs or other files that would cause
>> contention or loss of state. We don't seek to launch simultaneous
>> sessions. We just need to maintain the two installations, if possible.

I've been meaning to ask about this, didn't want to sound stupid:

>You're apparently running on Windows.  Whether it's "safe" depends entirely
>on what you do.  For example, due to the way Windows works, file extensions
>(like .py and .pyw) can be associated with only one executable, so if you're
>relying on stuff like "start program.py" working from a DOS box, it will
>pick up whichever version of Python you installed most recently.

File associations is no problem - people who enjoy such things can
have great fun arranging trick ways to send a .py file to various
different python.exe's (adding various shell commands, and/or
associating .py with something that reads the first line of the
file for the name of the executable as in UNIX...)

>I personally never use the registry for anything related to Python
>(including file extensions -- I never rely on them), and have at least half
>a dozen versions of Python installed on my Windows box.  No problem.

But Python itself seems to use the registry, for example it appears
that that's where it reads PYTHONPATH from. So sissys like me get
nervous installing a new version if we hope to keep the old one...
Right now it looks like all the Python stuff is under
HKEY_LOCAL_MACHINE/Software/Python/PythonCore/1.5. Presumably
if a person installed 2.x that would appear under PythonCore/2.x
without making any changes to PythonCore/1.5?

>> Related: Does the "Non-Administrative Install" option (under Advanced
>> Options in the 2.2 Wise Install Wizard) offer a straightforward way to
>> ensure the separation described above? That directs the DLLs to
>> be installed within the 2.2's own directory structure.
>
>The Windows Python DLLs for 2.2 and 2.1.1 have different names, so there's
>no conflict there.  Depending on user privilege and OS, it may not be
>*possible* to install the Python DLL into a system directory, and the
>Non-Admin install option is more aimed at that.  Non-Admin install also
>writes registry info under HKEY_CURRENT_USER instead of HKEY_LOCAL_MACHINE,
>which is again partly an issue of privilege, but also on Win2K is a way for
>each user on a machine to have their own file associations (a new feature in
>Win2K; can't be done under earlier OSes).
>
>


David C. Ullrich



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