code: def _generate_mark_code(rule_name):
      
      code = ''.join([i for i in str(rule_name) if i.isdigit()])
      code = code.zfill(2)
      return code
docs: Generates a two digit string based on a provided string
  
      Args:
          rule_name (str): A configured rule name 'pytest_mark3'.
  
      Returns:
          str: A two digit code based on the provided string '03'