字符串倒序

尽量多的写出字符串倒序的方法

# 1.纯循环
a = 'abcde'
n = len(a) - 1
dd = ''
while n >= 0:
    dd += a[n]
    n -= 1
dd
Out: 'edcba'

# 2.切片
a = 'abcde'
a[::-1]
Out: 'edcba'

# 3.列表
a = 'abcde'
aa = list(a)
aa.reverse()
''.join(aa)
Out: 'edcba'

# 4.列表切片
a = 'abcde'
aa = list(a)
aa[::-1]
''.join(aa)
Out: 'edcba'