Old code:
for x in y:
f(x)
New Code:
map(f, y)
Also use defaultdict instead of simple dict when advantageous and use list comprehensions
instead of for loops where map() could be used but requires lambdas.
svn: r14135
change [x for x in y if x] to filter(None, y)
change [f(x) for x in y] to map(f, x)
change [x for x in y] to list(y)
These changes reduce source code size and complexity and produce some minor performance gains
svn: r14104