Message 335961 - Python tracker (original) (raw)

Lib uses loops to append to a new list in quite a few places. I think it would be better to replace those with list comprehensions.

Benefits of this change:

• List comprehensions are generally more readable than appending to a newly created list

• List comprehensions are also a lot faster. Toy example: In [1]: %%timeit ...: l = [] ...: for i in range(5000): ...: l.append(i) 375 µs ± 1.73 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

  In [2]: %%timeit ...: l = [i for i in range(5000)] 168 µs ± 1.08 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)

Possible drawbacks:

• Refactoring can always introduce bugs and makes it harder to get meaningful output from git blame. In this case I think the diff is very manageable, making the changes easy to review.

Personally, I think the codebase would benefit from this change both in terms of some small performance gains and maintainability. I'd be happy to make a PR to fix this.