python中实现字符串翻转的方法

#字符串反转
def reverse (s):
  rt = ''
  for i in range(len(s)-1,-1,-1):
    rt += s[i]
  return rt

def reverse2 (s):
  li = list(s)
  li.reverse()
  rt = "".join(li)  return rt
def reverse3 (s):
  return s[::-1]
def reverse4 (s):
  return "".join(reversed(s))
from functools import reduce
def reverse5 (s):
  return reduce(lambda x,y:y+x,s)