GOTCHA with list comprehension

[Laura Creighton]

In a message of Wed, 05 Aug 2015 17:05:49 +1000, Chris Angelico writes:
>Incidentally, why Python 2.6? Python 2.7 has been out for a pretty
>long time now, and if you can't move to version 3.x, I would at least
>recommend using 2.7. Since the release of 2.6.9 back before Frozen
>came out, that branch has been completely unmaintained. Grab yourself
>a 2.7 and take advantage of some neat new features (for old values of
>"new"), and improved compatibility with 3.x.
>
>ChrisA

Be careful suggesting that people upgrade, at least until you have
found out that they aren't running CentOS enterprise edition. The
CentOS packaging system is utterly dependent on having the Python
version it expects, and if you install a more recent version
(from source, say) the whole packaging system will stop working.
Recovering from this problem is also very, very difficult  (unless
you just restore from a recent full backup).

Been there, done that. :(

Laura