gistfile1.py

>>> map(lambda (x, y): x + y, ([1, 2], [3, 4]))
[3, 7]
>>> map(lambda (x, y): x + y, [xrange(2)])
[1]
>>> def g():
...     yield 1
...     yield 2
... 
>>> map(lambda (x, y): x + y, [g()])
[3]
>>> # ... as long as it yields *exactly* two items
>>> map(lambda (x, y): x + y, [xrange(3)])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in <lambda>
ValueError: too many values to unpack