gistfile1.py

# mulander@craig-laptop:~/art/bench$ python test.py 
# 1.89928817749
# 1.24240493774
# mulander@craig-laptop:~/art/bench$ python test.py 
# 1.93834280968
# 1.26033616066
# mulander@craig-laptop:~/art/bench$ 

import timeit

def flatten_iter(entry):
	output = []
	for item in entry:
		for el in item:
			output.append(el)
	return output

def flatten_lcomp(entry):
	return [el for item in entry for el in item]


print timeit.timeit("flatten_iter([[1], [2,3,45], [1,3], [6], [8]])", setup="from __main__ import flatten_iter")
print timeit.timeit("flatten_lcomp([[1], [2,3,45], [1,3], [6], [8]])", setup="from __main__ import flatten_lcomp")