code: def clean(self, py_value):
          
          try:
              import bleach
              return bleach.clean(py_value, **self.__bleachOptions)
          except ImportError:
              warnings.warn('Unable to clean string column without webhelpers installed.')
              return py_value
docs: Cleans the value before storing it.
  
          :param:     py_value : <str>
  
          :return:    <str>