Steven D'Aprano <[EMAIL PROTECTED]> writes: > >> No, all(seq) is true if every element in seq is true. Surely that's a > >> more intuitive definition than your definition by what you can't do. > > They are different? > Of course they are different -- they differ in the case of an empty > sequence.
I don't think they differ in the case of an empty sequence. If the sequence is empty, both statements are true. > > By the definition, "all flying elephants are pink" and "all flying > > elephants are non-pink" are both true statements, if that's what > > you're asking. There is no contradiction. > > Of course there is a contradiction. The contradiction is that flying > elephants are simultaneously pink and not pink. Neither statement asserts the existence of any flying elephants regardless of color, so neither statement contradicts the other statement. > If you don't understand why "Foo is Bar" and "Foo is not Bar" can't both > be true simultaneously, I suggest you spend some time googling on > "noncontradiction logic". To get you started, here's the Wikipedia entry: > > http://en.wikipedia.org/wiki/Law_of_noncontradiction "All flying elephants are pink" is not a statement of the form "Foo is Bar". See <http://en.wikipedia.org/wiki/For_all>, as I've cited several times. "All flying elephants are pink" simply means "there are no non-pink flying elephants". "All flying elephants are non-pink" similarly means "there are no pink flying elephants". The statements don't contradict, and in fact both statements are true. > if husband.stopped_beating_wife(): # returns True or False > pay_fine() > else: > go_to_jail() > > Pretty hard on the innocent husbands who never even beat their wife at all. Correct. The code should not be written that way. > In hacker culture, the Chinese word > "mu" (literally "without") is sometimes used to mean "I cannot answer that > question because your assumptions are not correct". > > In the case of all(seq), the correct answer is "mu". I don't think it's that bad. We just have to spell out precisely what the assumptions are, and we've done so. -- http://mail.python.org/mailman/listinfo/python-list
