Python configparser config file 주석(comment) 유지

Python의 configparser 모듈로 config file을 읽고 쓰면 config file의 주석은 유지되지 않는다.

주석을 유지해야 할 때, 가능하도록 간단히 구현한 예시이다.

import configparser
 
def read_config_with_comments(file_path):
    """config file과 config file의 line을 함께 read"""
    with open(file_path, 'r') as file:
        lines = file.readlines()
 
    config = configparser.ConfigParser(allow_no_value=True)
    config.read(file_path)
 
    return config, lines
 
def write_config_with_comments(config, lines, output_file, space_around_delimiters=False):
    """config file 주석 유지"""
    existing_sections = set(config.sections())
    written_sections = set()
    current_section = None
    
    delimiters = "=" if not space_around_delimiters else " = "
 
    with open(output_file, 'w', encoding='utf-8') as file:
        for line in lines:
            stripped = line.strip()
 
            if stripped.startswith("#") or not stripped:
                file.write(line)
                continue
 
            if stripped.startswith("[") and stripped.endswith("]"):
                current_section = stripped.strip("[]")
                written_sections.add(current_section)
                file.write(line)
                continue
 
            if "=" in line and current_section:
                key = line.split("=", 1)[0].strip()
                if current_section in config and key in config[current_section]:
                    value = config[current_section][key]
                    file.write(f"{key}{delimiters}{value}\n")
                else:
                    file.write(line)  # Write original line if no updated value found
            else:
                file.write(line)
 
        for section in existing_sections - written_sections:
            file.write(f"\n[{section}]\n")
            for key, value in config[section].items():
                file.write(f"{key}{delimiters}{value}\n")
 
        for section in written_sections:
            for key, value in config[section].items():
                if key not in [line.split("=", 1)[0].strip() for line in lines if "=" in line]:
                    file.write(f"{key}{delimiters}{value}\n")