amalgamate multiple Python files into a single one

build.py

# - imports should only be in the format of "import <module> as <alias>",
#   if you do not want an alias, do "import stuff as stuff"
# - imports should only be in the top level scope

import os
import re

curr_dir_path = os.path.dirname(__file__)
main_path = os.path.join(curr_dir_path, "main.py")

delimiter = "\n" + "#" * 80 + "\n"
"""delimiter before and after included module"""

print(f"amalgamating {main_path}")

with open(main_path, "r") as mainf:
    main_text = mainf.read()

    included_modules_comment_list = []
    aliases = set(m for m in re.findall(r'import \w+ as (\w+)', main_text))
    amalgamated_modules = {}

    def replace(match):
        global aliases, included_modules_comment_list
        module = match.group(1)
        alias = match.group(2) if len(match.groups()) > 1 else module
        if module is not None:
            try:
                with open(os.path.join(curr_dir_path, module + ".py"), "r") as modulef:
                    if not module in amalgamated_modules:
                        print(f"including {module, alias}")
                        included_modules_comment_list += ["#   " + module]
                        return delimiter + f"# inserted module: {module}\n\n" + modulef.read().strip() + delimiter
                    else:
                        print(f"skipping {module}: already included")
                        return f'# skipped module {module}: already included'
            except:
                pass
            print(f"ignoring {module, alias}")
            aliases -= {alias}
            return f'import {module} as {alias}'

    main_text = re.sub(r'import (\w+) as (\w+)', replace, main_text)
    for alias in aliases:
        main_text = main_text.replace(alias + '.', '')

    with open(os.path.join(curr_dir_path, "_build_.py.txt"), "w") as f:
        f.write("\n".join(["# amalgamation of:", *included_modules_comment_list, f"#   main"]) + "\n\n")
        main_text = re.sub(r'#\s*<build-exclude>.*?</build-exclude>',
                           '# << excluded lines >>',
                           main_text, flags=re.DOTALL)
        f.write(main_text)