[Tutor] breeds of Python .....

[Modulok]

After following the reading suggestions, I soon found myself looking
at quite a few code examples that would only run under a particular
version of python.  Finally, I converted the example that I was
working on to run under Python3.  I just wondered if you guys would
advise a newbie like me to concentrate on Python3 or stay with Python2
and get into bad habits when it comes to change eventually?  Apart
from the print and input functions, I haven't so far got a lot to
re-learn.

Kind regards,        Barry.


Barry,

If you're just starting out, go with 3.x. If you have a need for some third
party modules that aren't yet available for 3.x, you'll have to stick with 2.x.
Most beginner tutorials will work without changes, except for the print
statement is now a function, e.g:

    print "foo"

Is now:

    print("foo")

There isn't a whole lot of difference in syntax to learn. Some modules have
been renamed, some module functions re-worked, etc. Probably the biggest change
is the move to all unicode strings. One thing you can do if you're running 2.x
but want to get into the 3.x swing of things is turn on 3.x warnings. It will
tell you if you did something the 2to3 tool can't automatically fix:

    python2.6 -3

If you want, you can actually use the 3.x style print function and true
division when using 2.x by putting this at the top of your code::

    from __future__ import print_function
    from __future__ import division

Now in 2.x, just like 3.x this will raise an exception:

    print "foo"     #<-- Now fails in 2.x
    print("foo")    #<-- Works.

-Modulok-