08 Sep 2006 17:33:20 -0700, Paul Rubin <"http://phr.cx"@nospam.invalid>: > [EMAIL PROTECTED] writes: > > print sum( ([i]*n for i,n in enumerate(seq)), []) > > Wow, I had no idea you could do that. After all the discussion about > summing strings, I'm astonished.
Why? You already had the answer: summing *strings*. Everything but strings can be summed by sum(). E.g.: Python 2.4.3 (#2, Apr 27 2006, 14:43:58) [GCC 4.0.3 (Ubuntu 4.0.3-1ubuntu5)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> class x(object): ... def __add__(self, other): ... return x(self.a + other.a) ... def __init__(self, a): ... self.a = a ... >>> t = x(10) >>> t.a 10 >>> sum([t, t]) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: unsupported operand type(s) for +: 'int' and 'x' >>> sum([t, t], t) <__main__.x object at 0xb7d6752c> >>> _.a 30 >>> sum([t, t], x(0)).a 20 >>> sum([t, t]*1000, t).a 20010 -- Felipe. -- http://mail.python.org/mailman/listinfo/python-list
