Running Python 2 and Python 3 on the same machine

[Paul Watson]

On Fri, 2008-12-05 at 02:10 +0100, "Martin v. Löwis" wrote:
> > Since the source code is incompatible, I was expecting the Python
> > executable to have a new name such as 'python3'
> 
> It does: the executable is called python3.0.
> 
> > or for the default
> > source code filename to change to '.py3' or something.
> 
> Such a proposal would be rejected. In a few years from now, Python 2
> will be gone, and we would be stuck with an ugly file extension
> (similar to how \windows\system is now an empty directory, and
> \windows\system32 actually contains the 64-bit binaries on x64)-
> 
> Regards,
> Martin

I have to agree with Terry; installing the released python-3.0.msi
results in an executable named 'python.exe' in the filesystem.  I have
not built it yet, but I assume the *NIX package results in a 'python'
executable file.

For a machine that runs existing Python 2.x applications, what should be
in the PATH variable?

For *NIX machines, will 'python' be placed into /usr/bin?  If so, then
the Python scripts that start out with a shebang like the following will
have difficulty.

#!/usr/bin/python
#!/usr/bin/env python

Has there been any guidance issued?