Python基础-小程序练习

一、 从第3层循环直接跳出所有循环

break_flag = False
count = 0
while break_flag == False:
    print("-第一层")
    while break_flag == False:
        print("第二层")
        while break_flag == False:
            count += 1
            if count > 10:
                break_flag = True
            print("第三层")
print("keep going...")

with break_flag

# break_flag = False
count = 0
while count < 3:
    print("-第一层")
    while count < 3:
        print("第二层")
        while count <= 10:
            count += 1
            # if count > 10:
            #     break_flag = True
            print("第三层")
print("keep going...")

without break_flag

二、 购物车程序

goods_list = [[‘Iphone7‘,5800],[‘Coffee‘,30],[‘Book‘,99],[‘Bike‘,199],[‘Vivi X9‘,2499]]     #商品列表
shopping_cart = []      #用户购物车列表
salary = int(input(‘input your salary:‘))       #用户薪水
m = salary
k = 0

while True:
    index = 0
    for goods in goods_list:        #打印商品列表
        print(index,goods)
        index += 1
    choice = input(‘>>>:‘).strip()
    if choice.isdigit():
        choice = int(choice)
        if choice >= 0 and choice < len(goods_list):
            goods = goods_list[choice]
            if goods[1] <= salary:      #判断用户是否带了足够的钱来支付所选商品
                shopping_cart.append(goods)
                salary -= goods[1]
                print(‘Add goods ‘+str(goods[0])+‘ into shopping cart! Your current balance:‘+str(salary))
            else:
                print(‘No enough money!The price is:‘+str(goods[1])+‘! Need more:‘+str(goods[1]-salary))
        else:
            print(‘Have no this goods!‘)
    elif choice == ‘q‘:
        print(‘----------Your shopping cart----------‘)
        print(‘ID   goods   quantity    price   total‘)
        for i in range(len(goods_list)):
            j = shopping_cart.count(goods_list[i])
            if j > 0 :
                k += 1
                print(k,‘\t‘,goods_list[i][0],‘\t‘,j,‘\t\t‘,goods_list[i][1],‘\t‘,j * goods_list[i][1])

        print(‘Total price is:‘,m - salary)
        break
    else:
        print(‘Have no this goods‘)

购物车程序