text: from cerberus import Validator
  
  
  def keys_and_values_are_strings(d):
      """
      Checks to see if the keys and values of this dict are strings.
      :param d: The Dictionary to check
      :return: Boolean, True if all the keys and values are strings.
      """
      schema = {
          'a_dict': {
              'keyschema': {'type': 'string'},
              'valueschema': {'type': 'string'}}
      }
      v = Validator(schema)
      return v.validate({'a_dict': d})
  