code: def open_python_file(filename):
      """Open a read-only Python file taking proper care of its encoding.
  
      In Python 3, we would like all files to be opened with utf-8 encoding. However, some author like to specify PEP263
      headers in their source files with their own encodings. In that case, we should respect the author's encoding.
  
      """
      import tokenize
  
      if hasattr(tokenize, "open"):  # Added in Python 3.2
          # Open file respecting PEP263 encoding. If no encoding header is
          # found, opens as utf-8.
          return tokenize.open(filename)
      return open(filename, encoding="utf-8")
  
imports: import inspect
  import os
  import sys
  import traceback
  import types
  from contextlib import contextmanager
  from copy import copy
  from typing import TYPE_CHECKING, Any, Dict, List, Tuple, Type, Union
  from lightning.app.utilities.exceptions import MisconfigurationException
  from lightning.app.utilities.app_helpers import Logger, _mock_missing_imports
label_desc: Use image node_id 6 for calling a global function with example usage: open_python_file(filename) and returns: open, tokenize