Python3实现：字符串反转

#方式一(切片)
astr = 'abcdef'
bstr = astr[::-1]
print(bstr)

#方式二
def myreverse(s):
    l = list(s)
    l.reverse()
    print("".join(l))

myreverse('abcdef')

#方式三（递归）
def myreverse1(s):
    if s == "":
        return s
    else:
        return myreverse1(s[1:]) + s[0]

print(myreverse1('abcdef'))

#方式四(逐个字符处理)
def myreverse2(s):
    t = ''
    r = len(s) - 1
    while r >= 0:
        t = t + s[r]
        r -= 1
    return t

print(myreverse2('abcdef'))