How to optimize this Python code (from ThinkPython, Exercise 10.10)

Question

I\'m working through Allen Downey\'s How To Think Like A Computer Scientist, and I\'ve written what I believe to be a functionally correct solution to Exercise 10.1

Answer 1

An important thing is your index function: It's the function that runs more than any function. When you don't need the index of the found word, why define a function to find that index?

if word1word2 in lst: is enough instead of if index(lst, word1word2):.

The same for if index(lst, word2word1):.

OK. bisection works really faster than the in syntax. To improve the speed a bit more, i suggest using the bisect_left function directly in your interlockings function.

For example instead of:

        if index(lst, word1word2): # check to see if word1word2 is actually a word
            total += 1
            print "Word 1: %s, Word 2: %s, Interlock: %s" % (word1, word2, word1word2)

Use:

        q = bisect_left(lst, word1word2)
        if q != len(lst) and lst[q] == word1word2:
            total += 1
            print "Word 1: %s, Word 2: %s, Interlock: %s" % (word1, word2, word1word2)

A very slight improvement in speed.