import os, sys


def convert(path):
    try:
        files_dirs = os.listdir(path)
        files_only = [ i for i in files_dirs if not os.path.isdir(i)]
        py_files = [i for i in files_only if i.endswith('.py')]
        print('found py files: ', py_files)
        print('[...] converting files ...')
        os.chdir(path)
        for file in py_files:
            convert_formula = file[:-3] + '.txt'
            print('converting: ', file)
            os.rename(file, convert_formula)
        print('[+] Done')
    except FileNotFoundError:
        print('[-] invalid path ! ')


convert(sys.argv[1])