https://www.runoob.com/python/python-strings.html

1 rsplit

rsplit反向分割 从右边分割 1

python
s = 'das dsa 123'
print(s.rsplit(' ',1))

outpuut：['das dsa', '123']

2 join 将序列中的元素以指定的字符连接生成一个新的字符串

python
res=[1,2,3]
print("-".join(map(str, res))+"end")

3 反向遍历字符串

python
rawstr = input()
res = []
for i in rawstr[::-1]: # 反向遍历
    if int(i) not in res:
        res.append(int(i))
print("".join(map(str,res)))

用列表反向

python
a=list(input())
a.reverse()
print("".join(a))

反向遍历

python
a = input()
res = ""
for i in a[::-1]:
    res += i
print(res)

4 是否有数字 大小写 长度

python
while True:
    try:
        line = input()
        a = 0
        b = 0
        c = 0
        d = 0
        flag = True
        for i in line:
            if i.isdigit():
                a = 1
            elif i.islower():
                b = 1
            elif i.isupper():
                c = 1
            else:
                d = 1
        for j in range(len(line) - 3):
            if line.count(line[j:j + 3]) > 1:
                flag = False
        if len(line) > 8 and (a + b + c + d) >= 3 and flag:
            print("OK")
        else:
            print("NG")
    except:
        break

5 格式化字符串

https://blog.csdn.net/qq_35085863/article/details/78188286

print(format(1, 'b').rjust(4, '0'))