code: def run_before_script(script_file, cwd=None):
      
      try:
          proc = subprocess.Popen(
              shlex.split(str(script_file)),
              stderr=subprocess.PIPE,
              stdout=subprocess.PIPE,
              cwd=cwd,
          )
          for line in iter(proc.stdout.readline, b''):
              sys.stdout.write(console_to_str(line))
          proc.wait()
  
          if proc.returncode:
              stderr = proc.stderr.read()
              proc.stderr.close()
              stderr = console_to_str(stderr).split('\n')
              stderr = '\n'.join(list(filter(None, stderr)))  # filter empty
  
              raise exc.BeforeLoadScriptError(
                  proc.returncode, os.path.abspath(script_file), stderr
              )
  
          return proc.returncode
      except OSError as e:
          if e.errno == 2:
              raise exc.BeforeLoadScriptNotExists(e, os.path.abspath(script_file))
          else:
              raise e
docs: Function to wrap try/except for subprocess.check_call().