python代码的帮助

我正在阅读一本名为python for software design的python书籍，它有以下练习：

假设一本书的封面价格是24.95美元，但书店可以得到40%的折扣。 第一份的运费是3美元，每增加一份75美分。什么 60份的总批发成本是多少

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)

由此，我得到以下结果：

包括运费和折扣在内的60本书的总价为： 这些书的总价是：898.2美元 总运费为：47.25美元 总价是：945.45美元

我的问题是：

这是正确的吗？ 我怎样才能使这个代码更好？

---

只有三件事需要改变：

1您复制了图书的数量：60和59都出现在代码中。你不应该有59个

2按如下方式打印结果：打印“总价为：%.2f%”结果

---

3通常的Python惯例是这样命名变量，而不是这样。

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，格式相同，小数点后有两位数字，总精度为7

---

编辑：当然，正如另一位所指出的，不要在那里硬编码59。

我觉得它很合适。我会避免硬编码。相反，检查总数是否不止一个，并根据需要进行划分

此外，这是次要的，但BookDeffortAmount应该是BookDeffortedAmount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。

请尝试以下方法：

#######################################################################################
#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)

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)

---

我是这样做的，但我仍然相信使用上面的功能会更好

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

---

我是python的初学者，这对我来说很好

这是我解决这个问题的基本方法

    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)

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))

---

它更多的是关于基础数学而不是Python…是的，我正在尝试学习语法、变量以及如何处理它们。一个建议是：不要在金钱上使用浮点。以美分记录所有价格。用美分做所有的计算。输出时转换成美元。是的，我读到浮点不是很精确。所以一个好的方法是做以下操作？shipping=shippingPriceRest*totalUnits-1+ShippingPriceFirst如果您尝试这样做，您会发现您需要包括一些参数，以便评估您的意思。是的，对不起，英语不是我的母语，谢谢您的提示%d？你试过这个代码吗？以增量方式添加装运的循环？为什么？您可能应该描述代码是如何比以前更好，以及最初的问题是它是否正确。

    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)

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))