On semi-related note, it's worth noting that if you're trying to make a Python script run faster and don't have the know-how to re-write your program in C or how to write SIMD (if applicable), you can always try to run the script through pypy, merely replacing python3 with pypy3 in bench.sh, with no other changes, brings the runtime of the first program down from 104s to 9s on my machine:

    Benchmark 1: python3 0_mvp.py bench.txt
      Time (mean ± σ):     104.739 s ±  3.982 s    [User: 104.213 s, System: 0.158 s]
      Range (min … max):   100.303 s … 108.005 s    3 runs
    Benchmark 2: python3 1_c_regex.py bench.txt
      Time (mean ± σ):     14.777 s ±  0.017 s    [User: 14.563 s, System: 0.158 s]
      Range (min … max):   14.759 s … 14.791 s    3 runs
    Benchmark 1: pypy3 0_mvp.py bench.txt
      Time (mean ± σ):      9.381 s ±  0.204 s    [User: 9.110 s, System: 0.234 s]
      Range (min … max):    9.245 s …  9.616 s    3 runs
    Benchmark 2: pypy3 1_c_regex.py bench.txt
      Time (mean ± σ):      4.296 s ±  0.031 s    [User: 4.038 s, System: 0.236 s]
      Range (min … max):    4.262 s …  4.324 s    3 runs

Thanks for the advice - I never heard of pypy. Are there any downsides to making puppy the default Python interpreter? Thanks!