docs: def _str2datetime(self, datetimestr):
          """Parse datetime from string. If no template matches this string,
          raise Error. Please go
          https://github.com/MacHu-GWU/rolex-project/issues
          submit your datetime string. I 'll update templates asap.
  
          This method is faster than :meth:`dateutil.parser.parse`.
  
          :param datetimestr: a string represent a datetime
          :type datetimestr: str
          :return: a datetime object
  
          **中文文档**
  
          从string解析datetime。首先尝试默认模板, 如果失败了, 则尝试所有的模板。
          一旦尝试成功, 就将当前成功的模板保存为默认模板。这样做在当你待解析的
          字符串非常多, 且模式单一时, 只有第一次尝试耗时较多, 之后就非常快了。
          该方法要快过 :meth:`dateutil.parser.parse` 方法。
          """
          if datetimestr is None:
              raise ValueError(
                  "Parser must be a string or character stream, not NoneType")
  
          # try default datetime template
          try:
              return datetime.strptime(
                  datetimestr, self.default_datetime_template)
          except:
              pass
  
          # try every datetime templates
          for template in DatetimeTemplates:
              try:
                  dt = datetime.strptime(datetimestr, template)
                  self.default_datetime_template = template
                  return dt
              except:
                  pass
  
          # raise error
          dt = parser.parse(datetimestr)
          self.str2datetime = parser.parse
  
          return dt