In article <85aba9h1e5....@dozer.localdomain>, J Kenneth King <ja...@agentultra.com> wrote: > Kottiyath <n.kottiy...@gmail.com> writes: > > I have the following list of tuples: > > L = [(1, 2), (3, 4, 5), (6, 7)] > > > > I want to loop through the list and extract the values. > > The only algorithm I could think of is: > >>>> for i in l: > > ... u = None > > ... try: > > ... (k, v) = i > > ... except ValueError: > > ... (k, u, v) = i > > ... print k, u, v > > --------- > > 1 None 2 > > 3 4 5 > > 6 None 7 > > ------------- > > But, this algorithm doesnt look very beautiful - like say -> for k, u, > > v in L: > > Can anyone suggest a better algorithm to get the values? > > Just a note: this isn't really an algorithm problem. ;) > > It's more of a grammar obstruction. > > To make your code more simple, it would be nice if the assignment > operator would return, "None," in the case where there are too few > values to unpack from the right-operand of the assignment operator.
Looks like the extended iterable unpacking feature of Python 3.0, described in PEP 3132, comes to the rescue here: >>> L = [(1, 2), (3, 4, 5), (6, 7)] >>> for i in L: ... k, *u, v = i ... print(k, u, v) ... 1 [] 2 3 [4] 5 6 [] 7 -- Ned Deily, n...@acm.org -- http://mail.python.org/mailman/listinfo/python-list
