20201231-1 购物车程序练习实例
作者：互联网
程序讲解：
商品列表是动态的，可能随时增加，减少，所以不能写死
Step1：打印商品列表
方式1
product_list = [
('Iphone',5800),
('Mac Pro',9800),
('Bike',800),
('Watch',10600),
('Coffee',31),
('Alex Python',120),
]
工资只输入一次，所以放循环外面
salary = input("Input your salary: ")
if salary.isdigit():
salary = int(salary)
while True:
for item in product_list:
print(product_list.index(item), item)
break
方式2
不通过下标，一个更直接的方法
product_list = [
('Iphone',5800),
('Mac Pro',9800),
('Bike',800),
('Watch',10600),
('Coffee',31),
('Alex Python',120),
]
salary = input("Input your salary: ")
if salary.isdigit():
salary = int(salary)
while True:
for index, item in enumerate(product_list):
print(index, item)
break
1. 关于 enumerate
>>> a = [1,2,3]
>>> for i in enumerate(a):print(i)
...
(0, 1)
(1, 2)
(2, 3)
每一个 i 都变成了 一个元组 第一个是小标，第二个是数据本身
enumerate 做的就是 取出了 列表的下标
Step2：根据用户选择做判断
product_list = [
('Iphone',5800),
('Mac Pro',9800),
('Bike',800),
('Watch',10600),
('Coffee',31),
('Alex Python',120),
]
shopping_list = []
salary = input("Input your salary: ")
if salary.isdigit():
salary = int(salary)
while True:
for index, item in enumerate(product_list):
print(index, item)
user_choice = input("选择要买嘛？>>>:")
if user_choice.isdigit():
user_choice = int(user_choice)
if user_choice < len(product_list) and user_choice >= 0:
# 接下来判断钱是否够用
p_item = product_list[user_choice]
if p_item[1] <= salary: # 买的起
shopping_list.append(p_item)
salary -= p_item[1]
print("Added %s into shopping cart, your current balance is %s" %(p_item, salary))
elif user_choice == 'q':
print('exit....')
else:
print("invalid option")
1. 如果想给结果变个颜色，红色 31，绿色 32
print("Added %s into shopping cart, your current balance is \033[31;1m%s\033[0m" %(p_item, salary))
这个就是死记,后面 \033[0m 一定要关闭
product_list = [
('Iphone',5800),
('Mac Pro',9800),
('Bike',800),
('Watch',10600),
('Coffee',31),
('Alex Python',120),
]
shopping_list = []
salary = input("Input your salary: ")
if salary.isdigit():
salary = int(salary)
while True:
for index, item in enumerate(product_list):
print(index, item)
user_choice = input("选择要买嘛？>>>:")
if user_choice.isdigit():
user_choice = int(user_choice)
if user_choice < len(product_list) and user_choice >= 0:
# 接下来判断钱是否够用
p_item = product_list[user_choice]
if p_item[1] <= salary: # 买的起
shopping_list.append(p_item)
salary -= p_item[1]
print("Added %s into shopping cart, your current balance is \033[31;1m%s\033[0m" %(p_item, salary))
elif user_choice == 'q':
print('exit....')
else:
print("invalid option")
2. 这是能买得起的情况，如果买不起呢？
product_list = [
('Iphone',5800),
('Mac Pro',9800),
('Bike',800),
('Watch',10600),
('Coffee',31),
('Alex Python',120),
]
shopping_list = []
salary = input("Input your salary: ")
if salary.isdigit():
salary = int(salary)
while True:
for index, item in enumerate(product_list):
print(index, item)
user_choice = input("选择要买嘛？>>>:")
if user_choice.isdigit():
user_choice = int(user_choice)
if user_choice < len(product_list) and user_choice >= 0:
# 接下来判断钱是否够用
p_item = product_list[user_choice]
if p_item[1] <= salary: # 买的起
shopping_list.append(p_item)
salary -= p_item[1]
print("Added %s into shopping cart, your current balance is \033[31;1m%s\033[0m" %(p_item, salary))
else:
print("\033[41;1m你的余额只剩[%s]啦，还买个毛线\033[0m"%salary)
2-1 31 和 41 的区别
32 是绿色，42 就是背景是绿色
elif user_choice == 'q':
print('exit....')
else:
print("invalid option")
3. 如果现在想退出了，打印已经买的产品
product_list = [
('Iphone',5800),
('Mac Pro',9800),
('Bike',800),
('Watch',10600),
('Coffee',31),
('Alex Python',120),
]
shopping_list = []
salary = input("Input your salary: ")
if salary.isdigit():
salary = int(salary)
while True:
for index, item in enumerate(product_list):
print(index, item)
user_choice = input("选择要买嘛？>>>:")
if user_choice.isdigit():
user_choice = int(user_choice)
if user_choice < len(product_list) and user_choice >= 0:
# 接下来判断钱是否够用
p_item = product_list[user_choice]
if p_item[1] <= salary: # 买的起
shopping_list.append(p_item)
salary -= p_item[1]
print("Added %s into shopping cart, your current balance is \033[31;1m%s\033[0m" %(p_item, salary))
else:
print("\033[41;1m你的余额只剩[%s]啦，还买个毛线\033[0m"%salary)
elif user_choice == 'q':
print("-------shopping list--------")
for p in shopping_list:
print(p)
3-1. 最后是退出，用exit()
print("Your current balance:",salary)
exit()
else:
print("invalid option")
4. 现在可以输入 6 应该如何处理？
product_list = [
('Iphone',5800),
('Mac Pro',9800),
('Bike',800),
('Watch',10600),
('Coffee',31),
('Alex Python',120),
]
shopping_list = []
salary = input("Input your salary: ") # 输入工资，判断是不是数字
if salary.isdigit(): # 如果是数字
# 如果输入的工资不是数字，就退出了，可以加 else 判断
salary = int(salary) # 将其int
while True:
for index, item in enumerate(product_list):
print(index, item)
user_choice = input("选择要买嘛？>>>:")
if user_choice.isdigit():
user_choice = int(user_choice)
if user_choice < len(product_list) and user_choice >= 0:
# 接下来判断钱是否够用
p_item = product_list[user_choice]
if p_item[1] <= salary: # 买的起
shopping_list.append(p_item)
salary -= p_item[1]
print("Added %s into shopping cart, your current balance is \033[31;1m%s\033[0m" %(p_item, salary))
else:
print("\033[41;1m你的余额只剩[%s]啦，还买个毛线\033[0m"%salary)
# 4-1 如果输入的数字不在范围内
else:
print("product code [%s] is not exist!"% user_choice)
elif user_choice == 'q':
print("-------shopping list--------")
for p in shopping_list:
print(p)
print("Your current balance:",salary)
exit()
else:
print("invalid option")
标签：salary,product,list,choice,item,实例,user,20201231,购物车 来源： https://blog.51cto.com/u_15149862/2834584