Python学习——A Day at the Supermarket小项目

最新推荐文章于 2025-01-08 09:23:43 发布

Amusi（CVer）

最新推荐文章于 2025-01-08 09:23:43 发布

阅读量901

点赞数

CC 4.0 BY-SA版权

分类专栏： Python 文章标签： python

本文链接：https://blog.youkuaiyun.com/amusi1994/article/details/55105924

Python 专栏收录该内容

24 篇文章

订阅专栏

本文介绍了一个简单的超市购物系统的实现过程，包括使用Python进行商品价格和库存管理，通过循环和条件判断来计算顾客购买商品的总金额，并更新库存。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

前言

A Day at the Supermarket该项目用来回顾/强化之前学习Python的知识点。

1、Before We Begin

names = ["Adam","Alex","Mariah","Martine","Columbus"]
for elements in names:
    print elements

上述代码，使用for循环，将names这个list中的items逐个输出/打印出来——遍历。

2、This is Key！

对dictionary使用for循环，输出是无序的，即每次输出，“key/value对”的顺序是无序的。

webster = {
	"Aardvark" : "A star of a popular children's cartoon show.",
    "Baa" : "The sound a goat makes.",
    "Carpet": "Goes on the floor.",
    "Dab": "A small amount."
}

# Add your code below!
for key in webster:
    print webster[key]

输出结果如下：

3、Control Flow and Looping

在循环中，有选择性地输出数据

a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]

for item in a:
    if item % 2 == 0:
        print item

4、Lists + Functions

函数可以将List作为其输入参数，进行下一步操作运算

任务：Write a function that counts how many times the string "fizz" appears in a list.

# Write your function below!
def fizz_count(x):
    count = 0
    for item in x:
        if item == "fizz":
            count += 1
    return count

fizz_count(["fizz","cat","fizz"])

5、String Looping

字符串和list类似，其每个字符相当于元素，所以字符串也可以像list一样循环操作。

可参见下述代码：

for letter in "Codecademy":
    print letter
    
# Empty lines to make the output pretty
print
print

word = "Programming is fun!"

for letter in word:
    # Only print out the letter i
    if letter == "i":
        print letter

6、Your Own Store!

创建一个价格dictionary——prices

prices = {
    "banana": 4, 
    "apple": 2, 
    "orange": 1.5, 
    "pear": 3
}

7、Investing in Stock

创建一个库存dictionary——stock

stock = {
    "banana": 6,
    "apple": 0,
    "orange": 32,
    "pear": 15
}

8、Keeping Track of the Produce

输出价格和库存信息

prices = {
    "banana": 4, 
    "apple": 2, 
    "orange": 1.5, 
    "pear": 3
}

stock = {
    "banana": 6,
    "apple": 0,
    "orange": 32,
    "pear": 15
}

for key in prices:
    print key
    print "price: %s" % prices[key]
    print "stock: %s" % stock[key]

9、Something of Value

将每种商品的总价格及所有商品的价格计算并打印出来

total = 0
for key in prices:
    print "prices: %s" % prices[key]*stock[key]
    total += prices[key]*stock[key]
print total

10、Shopping at the Market

groceries = ["banana", "orange", "apple"]

11、Making a Purchase

计算自己选购商品的价格

def compute_bill(food):
    total = 0
    for item in food:
            total += prices[item]
            stock[item] -= 1
    return total

12、Stocking Out

提示：If you're buying a banana, check if it's in stock (larger than zero). If it's in stock, add the cost of a banana to your bill. Finally, decrement the stock of bananas by one!

def compute_bill(food):
    total = 0
    for item in food:
        if stock[item] > 0:
            total += prices[item]
            stock[item] -= 1
    return total

13、Let's Check Out!

上述已经完成list、dictionary的创建

——Using for loops with lists and dictionaries
——Writing functions with loops, lists, and dictionaries
——Updating data in response to changes in the environment (for instance, decreasing the number of bananas in stock by 1 when you sell one).
完整代码如下：

shopping_list = ["banana", "orange", "apple"]

stock = {
    "banana": 6,
    "apple": 0,
    "orange": 32,
    "pear": 15
}
    
prices = {
    "banana": 4,
    "apple": 2,
    "orange": 1.5,
    "pear": 3
}

# Write your code below!
def compute_bill(food):
    total = 0
    for item in food:
        if stock[item] > 0:
            total += prices[item]
            stock[item] -= 1
    return total