#!/usr/bin/env python3 from os import environ, execvp, chdir, getcwd from os.path import exists, join, dirname from sys import version_info, argv def can_import(module_name): try: __import__(module_name) except ImportError: return False else: return True def is_python_3(): return version_info[0] >= 3 def is_current_version(file_name): version = map(int, file_name.replace("python", "").split(".")) return version == list(version_info)[:2] def launch_alternative(alternatives): for alternative in alternatives: if not is_current_version(alternative): for root in environ["PATH"].split(":"): if exists(join(root, alternative)): execvp(alternative, [alternative] + argv) def move_to_executable(): chdir(dirname(argv[0])) if "--go-to-dir" in argv: move_to_executable() from NS import NS NS().run()