l = range(int(1E9))

[Chris Angelico]

On Fri, May 1, 2015 at 7:23 AM, ElChino <elchino at cnn.cn> wrote:
> Mark Lawrence wrote:
>
>> You might find this useful then in you haven't already seen it
>> https://docs.python.org/3/howto/pyporting.html
>
>
> The main reason I haven't switched to Python3 (from 2.7.4/MSVC),
> is fear of a major breakage. How can I be certain that even if
> I install to different directories, the Python2 and Python3 won't
> step on each other toes. And what about all the .pyd I have around?
> Do they need an update?
>
> I'm barely familiar with virtualenv BTW; not sure another
> confusing factor in the equation would be a good idea. Or
> lessen my fear.

Very easily and simply: Python 3 and Python 2 will always install
separately, and the only possible conflicts are over the "python"
command in PATH and which program is associated with ".py" files. You
can fix both of them by installing a recent version of Python and
using the py.exe launcher:

https://www.python.org/dev/peps/pep-0397/
https://docs.python.org/3/using/windows.html#python-launcher-for-windows

As to your .pyd files... they'll continue to work with Python 2.7
(and, incidentally, I would suggest upgrading to 2.7.9 or 2.7.10), but
you'll need to update them for Python 3. If you got them from a third
party, chances are good that there'll be a Py3 build available; if you
built them from source, you could try just recompiling the latest
source. But if you wrote them yourself, you may well have to make some
changes to get them to compile against Python 3.

If you have issues, start a new thread; people will be happy to help.

ChrisA