def _shorten_file_path(line):
  """Shorten file path in error lines for more readable tracebacks."""
  start = line.lower().find('file')
  if start < 0:
    return line
  first_quote = line.find('"', start)
  if first_quote < 0:
    return line
  second_quote = line.find('"', first_quote + 1)
  if second_quote < 0:
    return line
  path = line[first_quote + 1:second_quote]
  new_path = '/'.join(path.split('/')[-3:])
  return line[:first_quote] + '[...]/' + new_path + line[second_quote + 1:]
Shorten file path in error lines for more readable tracebacks.