Examples of non-recursive function to flatten and sort a list. Keeping sorting by the way is greatly better because of timsort on Python.

flatten

#!/usr/bin/python

"""
Flatten a list
"""
def flatten(notflat):
	flat = []
	while notflat:
		element = notflat.pop()
		if isinstance(element, list):
		   notflat.extend(element)
		else:
		   flat.append(element)
	return flat.reverse()	

if __name__ == "__main__" :
	test = [1,2,[3,4],[5,6], [7], 8, [[[[1]]]], 2,3,[1,[2,[3],5],[7,[8],9]], [1,[2],[1,2,3,4]]]
	print flatten(test)
	# [1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 1, 2, 3, 5, 7, 8, 9, 1, 2, 1, 2, 3, 4]