一、 从第 3 层循环直接跳出所有循环
with break_flag
- 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...")
without 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...")
二、 购物车程序
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')
来源: http://www.bubuko.com/infodetail-2000988.html