Rewriting Recipe/410687 without map and lambda

[sofeng]

I would like to use the following recipe to transpose a list of lists
with different lengths. http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/410687

Here is an example of what I would like to do:

Python 2.5.1 (r251:54863, May 18 2007, 16:56:43)
[GCC 3.4.4 (cygming special, gdc 0.12, using dmd 0.125)] on cygwin
Type "help", "copyright", "credits" or "license" for more information.
>>> a = [[1,2,3],[4,5,6,7],[8,9]]
>>> print map(lambda *row: list(row), *a)
[[1, 4, 8], [2, 5, 9], [3, 6, None], [None, 7, None]]
>>>

However, in the Python 3000 FAQ (http://www.artima.com/weblogs/
viewpost.jsp?thread=211200), Guido says not to use map with lambda
because a list comprehension is clearer and faster.

How can I rewrite the above recipe using a list comprehension instead?

-sofeng