python如何翻转字符串？

>>> s = '123456'

>>> print(s[::-1])

654321

>>> s = '123456'

>>> ls = list(s)

>>> ls.reverse()

>>> ls

['6', '5', '4', '3', '2', '1']

>>> print(''.join(ls))

654321

>>> s = '123456'

>>> from functools import reduce

>>> reduce(lambda x,y:y+x,s)

'654321'

>>> reduce(lambda x,y:x+y,s)

'123456'