1 九九乘法表

for i in range(9):#从0循环到8    i += 1#等价于 i = i+1    for j in range(i):#从0循环到i        j += 1        print(j,'*',i,'=',i*j,end = ' ',sep='')        # end默认在结尾输出换行，将它改成空格 sep 默认 j,'*',i,'=',i*j 各元素输出中间会有空格    print()#这里作用是输出换行符

i = 1while i <= 9:    j = 1    while j <= i:        print("%d*%d=%d" % (j,i,i*j),end=' ') # 格式化输出        j += 1    i += 1    print()

2 登录程序

登录程序，有三次输入账号、密码的机会，错误三次账号锁定 user = 'hello world'paswd = 123456username = input("请输入用户名：")password = input("请输入密码:")for i in range(3):    if username == user and int(password) == paswd: #判断用户名和密码是否都匹配        print("欢迎您的到来")        break    elif i < 2:        username = input("请输入用户名：")        password = input("请输入密码")    elif i == 2:        print("账户已锁定")        break

3，购物车程序

功能：1，输入余额2，显示商品列表3，输入要购买的东西4，判断是否有能力购买5，是否继续6，输出已购买的商品和余额

shop_car = []#用来存放购买的商品goods = {    1:['手机',2500],    2:['电脑',3500],    3:['自行车',4500],    4:['宝马',20000]}#商品列表while True:    salary = input("你有多少钱：") # 输入有多少钱    if salary.isdigit(): # 判断是否为整数        salary = int(salary) # 将字符串转化为整数        print("是否要买东西：")        flag1 = input("Y      N:")        if flag1.upper() == 'N': # 将字符串大写            exit("欢迎下次光临") # 退出程序并输出“欢迎下次光临”        elif flag1.upper() == 'Y':            break                # 终止循环        elif flag1.upper() == 'Q':            exit("欢迎下次光临")    elif salary.upper() == 'Q':        exit("欢迎下次光临")while True:        print("淘宝".center(30,'-')) # 输出以-----淘宝------        for i in goods: # 循环输出            print(i,goods[i])        print("淘宝".center(30, '-'))        choice_good = input("请输入商品编码：")#接受一个字符串        if choice_good.isdigit() :            choice_good = int(choice_good)            if choice_good >= 1 and choice_good <= 4:                if salary >= goods[choice_good][1]:                    shop_car.append(goods[choice_good][0]) # 给字典中添加元素                    salary = salary - goods[choice_good][1]                    print("您购买的商品为：", goods[choice_good][0])                    print("余额为：", salary)                    print("是否继续：")                    contin = input("Y    N")                    if contin.upper() == 'N':                        break                    elif contin.upper() == 'Q':                        break                else:                    print('余额不足')                    print("是否继续：")                    contin = input("Y    N")                    if contin.upper() == 'N':                        break                    elif contin.upper() == 'Q':                        break            else :                print("没有这个编号")                continue # 暂停本次循环        elif choice_good.upper() == "Q" :            break        else:            print("我看不懂。。。")print("你买了：",end =' ')for i in shop_car:    print(i,end=' ')print()print("余额为：",salary)print("欢迎下次光临")