4 to 2 indentation

4to2.py

#!/usr/bin/python3

import sys
import re
def cv_indent(file: str) -> str:
  x = open(file, "r").read().strip().splitlines()
  print(f" *!reading: {len(x)} lines")

  code = ""
  for line in x: 
    space_ = re.search(r"^ *", line)
    tabs_ = re.search(r"^\t*", line)
    if space_:
      line = " " * (len(space_.group()) // 2) + line.removeprefix(space_.group())
      code += line + "\n"
    else:
      if tabs_:
        line = ("\t" * len(tabs_.group())) + line.removeprefix("\t" * len(tabs_.group()))
        code += line + "\n"
      else:
        if len(line) == 0:
          code += "\n"
        else: 
          code += line + "\n"

  print(f" *!writing: {len(code)} lines")
  open('out.py', "w", encoding="utf-8").write(code)
  return code

if __name__ == "__main__":
  sys.exit(cv_indent(sys.argv[1]))