函数中列表的总和

Question

我有一个关于 python 'functions' 编程的问题。

这是我的脚本：

def print_seat(seat):
        for item in seat:
                print "${}".format(item)
        print "-"*15
        total = get_seat_total(seat)
        print "Total: ${}".format(total)

def get_seat_total(seat):
        total = 0
        for dish in seat:
                total += dish
                return total

def main():
        seats = [[19.95], [20.45 + 3.10], [7.00/2, 2.10, 21.45], [7.00/2, 2.10, 14.99]]

        grand_total = 0

        for seat in seats:
                print_seat(seat)

                grand_total += get_seat_total(seat)
                print "\n"
        print "="*15
        print "Grand total: ${}".format(grand_total)

if __name__ == "__main__":
        main()

这是我的脚本结果：

$19.95
-----------
Total: $19.95

$23.55
-----------
Total: $23.55

$3.5
$2.1
$21.45
------------
Total: $3.5

$3.5
$2.1
$14.99
------------
Total: $3.5

============
Grand total: $50.5

但是脚本的结果应该是这样的：

$19.95
-----------
Total: $19.95

$23.55
-----------
Total: $23.55

$3.5
$2.1
$21.45
------------
Total: $27.05

$3.5
$2.1
$14.99
------------
Total: $20.59

============
Grand total: $91.14

从上面可以看出，列表中的总数是不同的。我想我写的所有东西都正确，包括列表的总和（如果我没记错的话）。有人可以指出我的脚本结构有什么问题吗？还是我脚本写错了？

Answer 1

问题在于，在您的 get_seat_total() 函数中，您是从循环内部返回的，因此它会在仅添加第一项后返回总数。您应该只在循环完成后返回，示例 -

def get_seat_total(seat):
    total = 0
    for dish in seat:
            total += dish
    return total

Answer 2

希望对你有帮助，

def print_seat(seat):
    for item in seat:
            print "${}".format(item)
    print "-"*15
    total = sum(seat)
    print "Total: ${}".format(total)

def main():
    seats = [[19.95], [20.45 + 3.10], [7.00/2, 2.10, 21.45], [7.00/2, 2.10, 14.99]]

    grand_total = 0

    for seat in seats:
            print_seat(seat)
            grand_total += sum(seat)
            print "\n"
    print "="*15
    print "Grand total: ${}".format(grand_total)

if __name__ == "__main__":
    main()

最好的，