other suggestions for more insighttry modifying the repetition counts used by these modulesor explore the alternative timeit module in python' standard librarywhich automates timing of codesupports command-line usage modesand finesses some platform-specific issues --in factwe'll put it to work in the next section you might also want to look at the profile standard library module for complete source code profiler tool we'll learn more about it in in the context of development tools for large projects in generalyou should profile code to isolate bottlenecks before recoding and timing alternatives as we've done here you might try modifying or emulating the timing script to measure the speed of the and set and dictionary comprehensions shown in the preceding and their for loop equivalents using them is less common in python programs than building lists of resultsso we'll leave this task in the suggested exercise column (pleaseno wagering )the next section will partly spoil the surprise finallykeep the timing module we wrote here filed away for future reference--we'll repurpose it to measure performance of alternative numeric square root operations in an exercise at the end of this if you're interested in pursuing this topic furtherwe'll also experiment with techniques for timing dictionary comprehensions versus for loops interactively in the exercises timing iterations and pythons with timeit the preceding section used homegrown timing functions to compare code speed as mentioned therethe standard library also ships with module named timeit that can be used in similar waysbut offers added flexibility and may better insulate clients from some platform differences as usual in pythonit' important to understand fundamental principles like those illustrated in the prior section python' "batteries includedapproach means you'll usually find precoded options as wellthough you still need to know the ideas underlying them to use them properly indeedthis module is prime example of this--it seems to have had history of being misused by people who don' yet understand the principles it embodies now that we've learned the basicsthoughlet' move ahead to tool that can automate much of our work the benchmarking interlude