> > This is purely sport question. I don't really intend to use the answer > > in my code, but I am wondering, if such a feat could be done. > > > > I have a following problem: I have a list based upon which I would > > like to construct a different one. I could simply use list > > comprehensions, but there is an additional trick: for some elements on > > this list, I would like to return two objects. For example I have a > > list of 0s and 1s and for 0 I would like to add 1 'a' and for 1 I > > would like to add 2 'b', like this: > > > > [1, 0, 0, 1] -> ['b', 'b', 'a', 'a', 'b', 'b'] > > > > The easy way is to return a tuple ('b', 'b') for 1s and then flatten > > them. But this doesn't seem very right - I'd prefer to create a nice > > iterable right away. Is it possible to achieve this? Curiosly, the > > other way round is pretty simple to achieve, because you can filter > > objects using if in list comprehension. > > > If you'll allow me a prior "import itertools", > > >>> [i for e in [1,0,0,1] for i in itertools.repeat('ab'[e], e+1)] > > does the job in 62 characters.
list("".join([("a","b"*2)[x] for x in [1,0,0,1]]) 50 characters. Do I win £5? -- http://mail.python.org/mailman/listinfo/python-list