code: def is_same_file (filename1, filename2):
      
      if filename1 == filename2:
          return True
      if os.name == 'posix':
          return os.path.samefile(filename1, filename2)
      return is_same_filename(filename1, filename2)
docs: Check if filename1 and filename2 point to the same file object.
      There can be false negatives, ie. the result is False, but it is
      the same file anyway. Reason is that network filesystems can create
      different paths to the same physical file.