code: def run(self, value):
          
          if self.pass_ and not value.strip():
              return True
  
          if len((value.strip() if self.strip else value)) != self.length:
              self.error = self.error.format(value, self.length)
              return False
          return True
docs: Determines if value character length equal self.length.
          Keyword arguments:
          value str -- the value of the associated field to compare