Question

理论上，我有一个运行Craigslist类型网站的代码。这是代码。

#Problem 4
choice = ()
while choice != 4:
    print "1. Add an item."
    print "2. Find an item."
    print "3. Print the message board."
    print "4. Quit."
    choice = input("Enter your selection:")
    if choice == 4:
        break

#Add an item
    if choice == 1:
        b = "bike"
        m = "microwave"
        d = "dresser"
        t = "truck"
        c = "chicken"
        itemType = raw_input("Enter the item type-b,m,d,t,c:")
        itemCost = input("Enter the item cost:")
        List = []
        List.extend([itemType])
        List.extend([itemCost])
        print List

用户应该能够输入1选择输入项目，再次按1并输入更多项目。如何在不覆盖先前输入的情况下保存列表？

Answer 1

首先，请勿使用List作为变量名称。它是Python中的内置类型。

您要覆盖之前输入的原因是每次用户输入时定义新列表1.在条件语句范围之外定义列表。

#Problem 4
itemList = []
choice = ()
while choice != 4:
    print "1. Add an item."
    print "2. Find an item."
    print "3. Print the message board."
    print "4. Quit."
    choice = input("Enter your selection:")
    if choice == 4:
        break

    #Add an item
    if choice == 1:
        b = "bike"
        m = "microwave"
        d = "dresser"
        t = "truck"
        c = "chicken"
        itemType = raw_input("Enter the item type-b,m,d,t,c:")
        itemCost = input("Enter the item cost:")
        itemList.append((itemType, itemCost))
        print itemList

如何在Python中向List添加多个项目？

1 个答案: