configurator.py

"""
Poor Man's Configurator. Probably a terrible idea. Example usage:
$ python train.py config/override_file.py --batch_size=32
this will first run config/override_file.py, then override batch_size to 32

The code in this file will be run as follows from e.g. train.py:
>>> exec(open('configurator.py').read())

So it's not a Python module, it's just shuttling this code away from train.py
The code in this script then overrides the globals()

I know people are not going to love this, I just really dislike configuration
complexity and having to prepend config. to every single variable. If someone
comes up with a better simple Python solution I am all ears.
"""

import sys
from ast import literal_eval

for arg in sys.argv[1:]:
    if '=' not in arg: #파일 입력받을때는 이거 if문 한번만 실행될 것
        # assume it's the name of a config file
        assert not arg.startswith('--') # --가 없어야 올바른 코드!
        #configuration을 --compile=False로 하나씩 지정안하고 파일로 할 것
        config_file = arg
        print(f"Overriding config with {config_file}:")
        with open(config_file) as f:
            print(f.read())
        exec(open(config_file).read())
        #read 함수는 파일내의 텍스트를 하나의 문자열로 반환하므로 그것을
        #한줄 한줄씩 실행해 주기 위해 exec를 쓴다. 
    else: #옵션 여러개 직접 지정했을 경우 else가 여러번 돌 것. 
        # assume it's a --key=value argument
        assert arg.startswith('--')
        key, val = arg.split('=')
        key = key[2:]
        if key in globals():
            try:
                # attempt to eval it it (e.g. if bool, number, or etc)
                attempt = literal_eval(val)
            except (SyntaxError, ValueError):
                # if that goes wrong, just use the string
                attempt = val
            # ensure the types match ok
            assert type(attempt) == type(globals()[key])
            # cross fingers
            print(f"Overriding: {key} = {attempt}")
            globals()[key] = attempt
        else:
            raise ValueError(f"Unknown config key: {key}")