帮助一个python代码答案

【问题标题】：Help with a python code帮助一个python代码
【发布时间】：2011-06-27 14:05:29
【问题描述】：

我正在阅读这本名为“Python for software design”的 Python 书籍，其中包含以下练习：

假设一本书的封面价格是 24.95 美元，但书店获得了 40% 的折扣。第一份运费为 3 美元，每增加一份运费为 75 美分。什么是 60 份的总批发成本

好的，我有以下代码：

bookPrice = 24.95
discount = .60
shippingPriceRest = .75
shippingPriceFirst = 3.00
totalUnits = 60

bookDiscountAmount = bookPrice * discount * totalUnits
shipping = shippingPriceRest * 59 + shippingPriceFirst

result = bookDiscountAmount + shipping


print 'The total price for 60 books including shipping and discount is: '
print 'Total price of the books is: ' + str(bookDiscountAmount)
print 'Total Shipping is: ' + str(shipping)
print 'The Total price is: ' + str(result)

我得到以下结果：

60本书的总价包括运费和折扣是：
图书总价：898.2
总运费为：47.25
总价为：945.45
我的问题是：
- 这是正确的吗？
- 我怎样才能使这段代码更好？

【问题讨论】：

更多的是基础数学而不是 Python...
是的，我正在尝试学习语法、变量以及如何处理它们。
一个建议：不要在金钱上使用浮点数。以美分记录所有价格。用美分进行所有计算。输出时转换为美元。
是的，我读到浮点数不是很精确

标签： python

【解决方案1】：

只有三件事需要改变：

1) 您重复了书籍的数量：60 和 59 都出现在代码中。那里不应该有 59。

2) 像这样打印你的结果：print 'The total price is: %.2f' % result

3) 通常的 Python 约定是命名 variables_like_this，notLikeThis。

【讨论】：

那么一个好方法是执行以下操作？ shipping = shippingPriceRest * totalUnits - 1 + shippingPriceFirst
如果你尝试这样做，你会发现你需要包含一些括号来评估你的意思。

【解决方案2】：

我建议的唯一改进是使用format-函数而不是字符串连接：

print """The total price for {0:d} books including shipping and discount is: 
         Total price of the books is: {1:7.2f} 
         Total Shipping is:           {2:7.2f} 
         The Total price is:          {3:7.2f}""".format(totalUnits, bookDiscountAmount
                                                         shipping, result)

这使得所有数字都很好地对齐并且格式相同（小数点后两位数，总精度为 7）。

编辑：当然，正如另一位指出的那样，不要在那里硬编码59。

【讨论】：

【解决方案3】：

在我看来是对的。我会避免硬编码 59。相反，检查总数是否大于 1，并酌情划分。

另外，这是次要的，但bookDiscountAmount 应该是bookDiscountedAmount（折扣是他们节省的金额，而不是他们支付的金额）。其他人已经指出了如何改进字符串打印。

【讨论】：

是的，对不起，英语不是我的母语，谢谢提醒

【解决方案4】：

我是这样做的，但我仍然相信使用上述功能会更好

price = 24.95
discount = price * (40/100)
d_price = price - discount
shipping = 3 + (0.75 * (60 - 1))
wholesale = d_price * 60 + shipping

【讨论】：

【解决方案5】：

请试试这个：

bookCost = 24.95
numBooks = 60.0

def cost(numBooks):
    bulkBookCost = ((bookCost * 0.60) * numBooks)
    shippingCost = (3.0 + (0.75 * (numBooks - 1)))
    totalCost = bulkBookCost + shippingCost
    print 'The total cost is: $', totalCost

cost(numBooks)

【讨论】：

【解决方案6】：

'''Suppose the cover price of a book is $24.95, but bookstores get a 40%
discount. Shipping costs $3 for the first copy and 75 cents for each
additional copy. What is the total wholesale cost for
60 copies?
'''
import math

book_price = float(24.95)

discount = float(book_price * 40 /100)

Book_Price= float(book_price - discount)
print ('Book Price is without shipping charges = ' , Book_Price)

shipping = 3.0

Total_Price = float(Book_Price + shipping)

print ('The book 1st price is =' ,Total_Price)

Quantity = int(input('Enter the Number of Copies = '))

if Quantity > 1:

   Price = float(Book_Price * Quantity)
   Additional_copy_price = 0.75
   Q = float(Quantity * Additional_copy_price) 
   Final_Price = float(Price + Q + 3 - .75)

   print (' Final price for more than one copy is  = ' , Final_Price)

else:
   print (Total_Price)

【讨论】：

【解决方案7】：

cov_price = 24.95                            #cost of one book
discount = 0.4
per_one = (cov_price-(cov_price*discount))   #cost of one book on discount
ship_cost = 3                                #shipment on first book
other_ship = 0.75                            #shipment on other books

purchased = input("Enter number of books purchased : ")
purchased = int(purchased)

if(purchased):
   cost = ((other_ship*(purchased-1)+(per_one*(purchased-1))) + (per_one+3))
   print("The cost of books purchased including discount = ",cost)
   print("Price per one is =",per_one)

我是 python 的初学者，这对我来说很好用

【讨论】：

【解决方案8】：

    bc = 24.95    #book cost real price
dis = 0.40    # discount percent
bcd = bc*dis  # discount amount
bp = bc - bcd # book price

scf = 3       # shipping cost for the first book
scr = 0.75    # shipping cost for the rest books

cost1 = bp*scf
cost2 = bp*scr*59
TotalCost = cost1 + cost2
print(TotalCost)

【讨论】：

您可能应该描述代码比以前更好的地方，以及原始问题是否正确。

【解决方案9】：

这是我对这个问题的基本解决方案

price = 24.95 - (24.95)*4/10
order = 60
shipping = 3 + 0.75*(order-1)
print('The total price for 60 books including shipping and discount is %.2f$' % (order*price + shipping))

【讨论】：

【解决方案10】：

n = int(input('Enter the number of copies : '))

Book_store_price_of_one_copy = (60*24.95)/100

Shipping_cost_for_copy = (3+((n-1)*0.75))

whole_sale = (n*Book_store_price_of_one_copy)+Shipping_cost_for_copy

print(f'Whole sale of {n}  copies is {whole_sale}')

【讨论】：

嗨，欢迎来到 Stackoverflow！下一次，请尝试解释代码的每个部分的作用，或者至少解释它是如何回答问题的。它使那些再次偶然发现您的代码的人更容易。谢谢！

【解决方案11】：

#######################################################################################
#Your code, commented
#######################################################################################

bookPrice = 24.95
discount = .60
shippingPriceRest = .75
shippingPriceFirst = 3.00
totalUnits = 60

bookDiscountAmount = bookPrice * discount * totalUnits # Poor variable name choice. This is not the book discount amount, it's the cost of all books without shipping
shipping = shippingPriceRest * 59 + shippingPriceFirst # You should really use your variables as much as possible. Instead of 59, use totalUnits - 1

result = bookDiscountAmount + shipping


print 'The total price for 60 books including shipping and discount is: '
print 'Total price of the books is: ' + str(bookDiscountAmount)
print 'Total Shipping is: ' + str(shipping)
print 'The Total price is: ' + str(result)

#######################################################################################
#An example of your code, cleaned up
#######################################################################################

bookPrice = 24.95
discount = .60
shippingPriceRest = .75
shippingPriceFirst = 3.00
totalUnits = 60

totalCostBeforeShipping = (bookPrice * discount) * totalUnits
shipping = (shippingPriceRest * (totalUnits-1)) + shippingPriceFirst

result = totalCostBeforeShipping + shipping

print 'The total price for 60 books including shipping and discount is: '
print 'Total price of the books is: ' + str(totalCostBeforeShipping)
print 'Total Shipping is: ' + str(shipping)
print 'The Total price is: ' + str(result)

#######################################################################################
#An example of another method, using a loop
#######################################################################################

bookPrice = 24.95
discount = 40 # %
bookPriceWithDiscount = bookPrice * ((100.0-discount)/100.0)
firstBookShippingPrice = 3
otherBookShippingPrice = .75
totalBooks = 60

totalCost = 0

for book in range(totalBooks):
    if book == 0:
        totalCost += firstBookShippingPrice
    else:
        totalCost += otherBookShippingPrice

    totalCost += bookPriceWithDiscount

shipping = firstBookShippingPrice + (otherBookShippingPrice * totalBooks)

print 'The total price for 60 books including shipping and discount is:'
print 'Total price per book is: %d'%(bookPriceWithDiscount)
print 'Total shipping is: %d'%(shipping)
print 'The total price is: %d'%(result)

【讨论】：

%d ?你试过这个代码吗？一个循环增加运费？为什么？？