Multiple Version Install?

[Tim Peters]

[David C.Ullrich]
> Would there be issues (registry settings, environment
> variables, whatever) if a person tried to install
> versions 1.x and 2.x simultaneously on one Windows
> system? Windows 98, if it matters.
>
> (I can handle the file associations with no problem.)

There are generally no issues beyond file associations.  On Windows,
Python versions i.j.k and i'.j'.k' coexist happily so long as i != i'
or j != j'.  For example, I currently have the python.org-released
Pythons 2.2.3, 2.3.5, and 2.4.3 installed on my Windows box.  It would
be a challenge only if I wanted, say, 2.4.2 and 2.4.3 installed
simultaneously.

Another possible issue is that whenever the major or minor version
numbers (i or j) change on Windows, you also need to install matching
versions of any 3rd party extensions you want.  The major and minor
version numbers appear in the _name_ of the core Python DLL (like
python23.dll and python24.dll), and extensions with C code must be
compiled to link with the correct version of the Python DLL.

> If anyone feels like pointing out that there's simply
> no reason to want to keep 1.x after installing the
> current version: By all means talk me into that!

If you've been using extensions with 1.j.k, then as above they have no
chance of working with 2.j'.k' bejore you install 2.j' versions of
those extensions.  That's a good reason to keep an old version.

There have been thousands of bugfixes and language enhancements since
1.j.k too, and not all are 100% backward-compatible.

In all, best advice is to keep the old version around until you're
sure you no longer need it.

> The problem is not that I'm concerned about backwards
> compatibility of Python code. The problem is that I
> use Python embedded in various Delphi programs,
> including a "DIDE" that I use really a lot, via
> a certain set of Delphi "components". These components
> don't seem to work with 2.x. Presumably the PyDelphi
> people have new versions of the components that do
> work with Python 2.x. These presumably use much
> newer versions of Delphi than what I have. A new
> version of Delphi is not free... If I could use
> Python 2.x when I need to while continuing to
> use 1.x the way I have been for things that
> don't need 2.x that would be convenient.

That should work fine.  I don't know about PyDelphi, but found what
appears to be a still-active discussion list:

    http://groups.yahoo.com/group/pythonfordelphi/

The theoretical joy of open source is that if they _don't_ support the
Python+Delphi combo you have, you can fix that yourself ;-)