Python如何利用遍历构造列表逆转字符串？

#!usr/bin/env python
# encoding:utf-8
def strReverse(strDemo):
  strList=[]
  for i in range(len(strDemo)-1, -1, -1):
    strList.append(strDemo[i])
  return ''.join(strList)
print(strReverse('qbitschool.cn'))