Do 2.2 and 2.1.1coexist well?

David C. Ullrich ullrich at
Tue Dec 4 13:23:54 EST 2001

On Mon, 3 Dec 2001 14:32:37 -0500, "Tim Peters" < at>

>[David C. Ullrich, about Python on Windows]
>> I've been meaning to ask about this, didn't want to sound stupid:
>I've meaning to answer this, but likewise didn't want to sound stupid.

Just append something about floating point or better yet
indentation... you always sound like a smart guy when you talk
about that stuff.

>> ...
>> 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...)
>> ...
>> But Python itself seems to use the registry, for example it appears
>> that that's where it reads PYTHONPATH from.
>It's complicated.  You can read the comments at the start of PC\getpathp.c,

Nope, don't know any C...

>and I know of know way to summarize that usefully.  In fact, Python on
>Windows normally never reads the registry for anything,

Fabulous. This business of programs that aren't smart enough to run
themselves has always seemed stupid. (The install just writes stuff
to the registry for the sheer thrill of it, eh?)

> not even for
>PYTHONPATH.  You can verify that by changing the PYTHONPATH in your
>registry, and then noting that sys.path doesn't change as a result.  The
>PYTHONPATH in the registry is a backup in case all other attempts to locate
>Python's home directory fail (which can happen if, e.g., Python components
>are invoked via COM by some other app).  


>(OTOH, it could be the rules have
>changed since the ancient version of Python you're still torturing yourself
>with <wink>.)

Well, it still works...

>> 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?
>Yes, although, as above, these registry entries normally aren't used.

Thanks. Oh boy, 2.x.

David C. Ullrich

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