1.使用字符串切片
>>> def reverse1():
... s = input("please input a string: ")
... return s[::-1]
...
>>> reverse1()
please input a string: yangyue!
'!euygnay'
2.使用递归
>>> def reverse2(s):
... if s == "":
... return s
... else:
... return reverse2(s[1:]) + s[0]
...
>>> s = 'yangxinyue'
>>> reverse2(s)
'euynixgnay'
3.使用列表的reverse
>>> def reverse3(s):
... l = list(s)
... l.reverse()
... print("".join(l))
...
>>> reverse3('yangxinyue')
euynixgnay