Tweak AF*

(* means also buggy and WIP AF!!!)

Python "library" for live coding and tweaking long (already) running scripts (ML training, crawlers).

• Have you ever wanted to tweak some constants in your code, WHICH IS ALREADY RUNNING?
  • use tweak_af.tv() !!!
    • as a bonus, tv() can be easily broken by adding new lines to your script!!!
• Have you ever wanted to rewrite some function in your code, WHICH ALREADY STARTED?
  • use tweak_af.tf() !!!

Lets see examples: or you can check example.py

Tweakable values: (inspired by https://github.com/joeld42/ld48jovoc/blob/master/util/tweakval/tweakval.cpp and friends)

TODO: fancy GIF here

• code it (test_tv.py):

    from tweak_af import tv

    while True:
        print(tv(0))

• run it: python test_tv.py & (in the background, not necessary, but you can use same terminal for editing)

  • you will see that it prints all zeroes

• while it is running, edit the code and rewrite it from tv(0) to tv(42) (or whatever) and save it as usual

  • see that the script, which is still running, now prints your new value!!!
  • Note: if you add new lines before any tv() call (while script is running), its logic will be broken
  • Note 2: value is evaluated by eval() call, so if there is some exception thrown, it will crash your running script

Tweakable functions:

TODO: fancy GIF here

• code it (test_tf.py):

    from tweak_af import tf
    
    def test_func(a, b):
        return a + b
        
    while True:
        print(tf(lambda: test_func(1, 2)) # yeah, lambda is actually needed, because reasons

• run it: python test_tf.py & (in the background, not necessary, but you can use same terminal for editing)

  • it will print, you guessed right, 3s

• while it is still running, edit the code

  • so, rewrite the test_func() to be like return a + b + 1
  • save it from wherever you want

• now, you get 4s instead of 3s

  • Note: you can add more lines to the functions in runtime
  • Note 2: you can add new functions and call them from existing tf() functions, which you edit
  • Note 3: you can use tv() inside of tf() functions, but maybe it will break :-)

Tests:

• chmod u+x test.sh
• run test.sh (or only test_tf.sh, test_tv.sh), if they exit, it probably means that this library works

Notes:

• methods not supported (yet)
• tested only for Python 3.8 on WSL 2 and macOS 10.14.6 (Mojave)
• you can disable dynamic behavior by set_tweakables_enabled(False), in this case, it will use defaults
• very buggy, poorly written
• this will break debugger (expected)
• not CPU efficient and memory friendly
  • use only for simpler use cases (few functions/values as tf()/tv()) or not in production code
• use at your own risk, there are no guarantees

TODOs:

• use fs_notify/inotify and reload dictionaries only when backing file changes
• better tests without bash usage
• method support
• startup and tweak as a service business /sarcasm
• provide licence (probably MIT or BSD one)
• use GIFs for README!
• fix all the FIXMEs and TODOs! (which basically means rewriting everything in more pythonic and efficient way)
• pip package
• make README.md more fancy and readable