Python02 分支结构

一、If语句密码

1.有数字必须含有大写字母和小写字母

password = 'A12'
A = 'ZXCVBNMASDFGHJKLQWERTYUIOP'
B ='zxcvbnmasdfghjklqwertyuiop'
C = '1234567890'

count1,count2,count3 = False,False,False
for i in password:
    if i in A:
        count1 = True
    if i in B:
        count2 = True
    if i in C:
        count3 = True
if count1 and count2 and count3:
    print('OK')
else:
    print('必须含有大写小写和数字')
2.计算器
num1,num2 = map(float,input('Num1,Num2:').split(','))
choose_method = input('Choose Method:[+,-,*,/]')
if choose_method in '+-*/':
    if choose_method == '+':
        print('%.2f + %.2f = %.2f'%(num1,num2,num1 + num2))
    elif choose_method == '-':
        print('%.2f - %.2f = %.2f'%(num1,num2,num1 - num2))
    elif choose_method == '*':
        print('%.2f * %.2f = %.2f'%(num1,num2,num1 * num2))
    else :
        print('%.2f / %.2f = %.2f'%(num1,num2,num1 / num2))
else:
    #抛出错误
    raise KeyError('Only choose [+,-,*,/]')
二、for in 循环

range 是前闭后开的

1.银行卡密码
用户只能输入三次密码,如果密码错误则锁定账号

ini_passward = 100000
input_ = int(input('请输入密码>>:'))

for i in range(2):
    if input_ == ini_passward:
        print('OK')
        break
    else:
        print('密码错误,请尝试重新输入')
        input_ = int(input('请输入密码>>:'))
else:
    print('账号锁定,请移步至柜台')
2.验证码

生成：纯小写字母验证码4位.

         数字字母混合验证码4位,

         3次机会

import random
# 随机产生给予范围之内的随机数字.
for i in range(3):
    yanzhengma = random.randrange(1000,9999)
    print('验证码为: %d' % yanzhengma)
    input_ = int(input('请输入验证码>>:'))
    if input_ == yanzhengma:
        print('欢迎您,您真是一个小天才.')
        break
    else:
        print('验证码错误,请尝试重新输入')