gistfile1.txt

import time

input = ['a', 'b', 'c', 'd', 'e', 'f']
iterations = 1000000

start = time.time()
for i in xrange(iterations):
    s = dict([(x.lower(), i) for i, x in enumerate(input)])
end = time.time()
print "First thing took %s seconds" % (end - start)

start = time.time()
for i in xrange(iterations):
    s = dict((x.lower(), i) for i, x in enumerate(input))
end = time.time()
print "second thing took %s seconds" % (end - start)