This bothers me. You seem to have some kind of syntax error here, because you have two parens before the colon. I don't know if you meant to do this, but it seems very, very strange the way you have it, and the obvious alternative seems strange as well:
No, the "extra" parenthesis is intentional. The original expression must terminate before the block begins. Not having the parenthesis there would mean that it needs to be added to end of the block, but then it wouldn't be the indentation that controls the block but the parenthesis, and that's unpythonic. The original idea I had was to have a special keyword for "variable which I will define on the next line, just wait a minute please" but then I simplified it down to @ on analogy to decorators. Still, some people might like the original idea more:
words = ["blah one", "Blah two", " bLAh three"] sorted(words, key=DEFERRED) def DEFERRED(word): ... word = word.lower() ... word = word.replace("one", "1") ... word = word.replace("two", "2") ... word = word.replace("three", "3") ... word = word.replace(" ", "") ... return word ... [u'blah one', u'Blah two', u' bLAh three']
And then we just have to fight about what would be a good keyword or symbol for "deferred."