Question

#ask the user for how many books they would like
def books_needed():
    number_books = int(raw_input("How many books would you like?:"))
    if number_books <0 or number_books >80:
        number_books = raw_input(int("Number of books cannot be less than 0 or greater than 80. Enter another number:"

#calculates the cost of the books
def calculation1(number_books):
    cost_books = number_books * float(15.99)
    return cost_books

#selects the correct discount percentage to apply
def calculation2(number_books):
    if number_books <= 51 and number_books >= 81:
        discount = int(10)
    elif number_books <=11 and number_books >= 50:
        discount = float(7.5)
    elif number_books <= 6 and number_books >= 10:
        discount = int(5)
    elif number_books <= 1 and number_books >= 5:
        discount = int(1)
    return discount

#works out the cost of books divided by 100
def calculation3(discount,cost_books):
    total = cost_books/100
    return total

#multiplies the number by the correct discount
def calculation4(total,discount):
    full_discount = total * discount
    return full_discount

#calculates the total cost of the books including discount
def calculation5(full_discount):
    final_cost = cost_books - full_discount
    return final_cost

#displays the result
def display_results(final_cost):
    print
    print"Your final price is £", final_cost

#main program
books_needed()
cost_books = calculation1(number_books)
discount = calculate2(number_books)
total = calculation3(discount,cost_books)
full_discount = calculation4(total,discount)
final_cost = calculation5(full_discount)
display_results(final_cost)

准确地说，对def的计算1发生错误。如果需要，可以复制确切的错误。据我所知，其余程序还可以。如果出现其他任何问题，请告诉我。感谢

Answer 1

您忘记了上一行的一些右括号：

number_books = raw_input(int("Number of books cannot be less than 0 or greater than 80. Enter another number:"
#   two opening parens 1^  2^        but at the end here ---------------------------------- no closing parens ^

您需要在那里添加两个 )个字符，以关闭int()和raw_input()来电：

number_books = raw_input(int("Number of books cannot be less than 0 or greater than 80. Enter another number:"))

然而，这仍然是错误的，因为"Number .."字符串不能转换为整数。您可能希望将两个调用反转为：

number_books = int(raw_input("Number of books cannot be less than 0 or greater than 80. Enter another number:"))

将raw_input()（用户输入）的返回值转换为整数。

其他说明：

您无需将数字文字转换为float()和int()：

cost_books = number_books * 15.99  # 15.99 is a float already

discount = 10    # 10 is an integer already

discount = 7.5   # 7.5 is a float already

您的books_needed()函数不会返回任何内容。从函数返回number_books以便稍后使用。在您拥有有效数字之前，请使用循环继续询问数字：

def books_needed():
    while True:
        try:
            number_books = int(raw_input("How many books would you like?:"))
            if 1 <= number_books <= 80:
                return number_books
        except ValueError:
            # not a number, at all
            pass
        print "Number of books must be between 1 and 80."

然后在最后使用：

number_books = books_needed()

Answer 2

raw_input之前的def上没有右括号。这就是造成你问题的原因。

最重要的是，您有raw_input和int转置。前者获取字符串，后者将其转换为整数。因此它应该是：

int (raw_input( ...

Answer 3

你不应该在行中使用raw_input：number_books = int（raw_input（“你想要多少本书？：”））

相反你应该只使用输入：number_books = input（“你想要多少本书？：”）

程序在def计算1上返回语法错误

3 个答案: