code: def _pwd() -> str:
      root = "/"
  
      if not os.path.exists(_CD_FILE):
          with open(_CD_FILE, "w") as f:
              f.write(root + "\n")
      else:
          with open(_CD_FILE) as f:
              lines = f.readlines()
              root = lines[0].replace("\n", "")
  
      return root
  
file_path: pytorch-lightning/src/lightning/app/cli/commands/pwd.py
imports: import os
  import sys
  from rich.live import Live
  from rich.spinner import Spinner
  from rich.text import Text
  from lightning.app.cli.commands.cd import _CD_FILE
  from lightning.app.utilities.app_helpers import Logger
label_desc: Use image node_id 2 for calling a global function with example usage: _pwd() and returns: root