map(function, sequence) calls function(item) for each of
the sequence's items and returns a list of the return values. For
example, to compute some cubes:
>>> map(lambda x: x*x*x, range(1, 11))
[1, 8, 27, 64, 125, 216, 343, 512, 729, 1000]
>>>
More than one sequence may be passed; the function must then have as
many arguments as there are sequences and is called with the
corresponding item from each sequence (or None if some sequence
is shorter than another). If None is passed for the function,
a function returning its argument(s) is substituted.
Combining these two special cases, we see that
map(None, list1, list2) is a convenient way of turning a pair
of lists into a list of pairs. For example:
>>> seq = range(8)
>>> map(None, seq, map(lambda x: x*x, seq))
[(0, 0), (1, 1), (2, 4), (3, 9), (4, 16), (5, 25), (6, 36), (7, 49)]
>>>