Question

我正在研究简单的购物车代码，该代码可以从名为Shopping Cart.txt的文本文件中读取和写入。

我可以写入文件，但不能从其中删除。该代码在删除时不会产生任何错误，但不会同时删除。有人可以指出我正确的方向吗？

代码如下：

file = open('/Users/dsmith/Shopping list.txt', 'w')
file.write("Shopping list\n")
file.close()

print("Welcome to the shopping list creator")
print()

def shoppinglist():
    print('''Choose 1 to view your shopping list.
Choose 2 to add an item to your shopping list.
Choose 3 to delete an item from your shopping list.
Choose 4 to exit the program.''')
    print()
    choice = int(input("Enter your choice: "))

    if choice == 1:
        shoppinglist_file = open('/Users/dsmith/Shopping list.txt')
        print()
        print(shoppinglist_file.read())
        print()
        shoppinglist_file.close()
        shoppinglist()

    elif choice == 2:
        shoppinglist_file = open('/Users/dsmith/Shopping list.txt', 'a')
        print()
        thing_to_add = str(input("What would you like to add to your shopping list? "))
        shoppinglist_file.write("%s" % (thing_to_add))
        shoppinglist_file.close()
        print()
        shoppinglist()

    elif choice == 3:
        shoppinglist_file = open('/Users/dsmith/Shopping list.txt')
        shoppinglistfile_list = shoppinglist_file.readlines()
        print()
        print(shoppinglistfile_list)
        del_item = str(input)
        print(del_item)
        shoppinglistfile_list.remove(del_item)
        print()
        shoppinglist()

    elif choice == 4:
        print()
        print("Thank you for using ths program")
        print("--------")

    else:
        print()
        print("Please enter a valid option")
        print()
        shoppinglist()


shoppinglist()

Answer 1

从文件中删除后，您不保存更改。在

之后添加代码

shoppinglistfile_list.remove(del_item)

应该有帮助。

shoppinglist_file.close()
shoppinglist_file = open('/Users/dsmith/Shopping list.txt', 'w')
shoppinglist_file.write(shoppinglistfile_list)
shoppinglist_file.close()

以上代码以写模式重新打开文件，然后将购物清单写回，但删除的单词除外。

购物车说不清-Python

1 个答案: