On 2016-06-23, Chris Angelico <ros...@gmail.com> wrote: > On Thu, Jun 23, 2016 at 8:15 PM, BartC <b...@freeuk.com> wrote: >> Actually pretty much any expression can be used, because Python can >> interpret almost anything as either True or False. Don't ask for the rules >> because they can be complicated, but for example, zero is False, and any >> other number is True. I think. > > The rules are very simple. Anything that represents "something" is > true, and anything that represents "nothing" is false. An empty > string, an empty list, an empty set, and the special "None" object > (generally representing the absence of some other object) are all > false. A string with something in it (eg "Hello"), a list with > something in it (eg [1,2,4,8]), etc, etc, are all true.
Exactly. This is a major everyday strength of Python in my view. I seem to recall that Java originally insisted that only booleans (excluding even Booleans, which are a different thing because of course they are) could be checked for truth and it was one of Java's significant warts. -- https://mail.python.org/mailman/listinfo/python-list
