删除lin后更新文件

Question

我已经写了一个简单的程序与文件处理来模拟库存。用户可以捡起、放下或查看库存。drop函数工作不正常

f = open("inv.data.txt", "a+")
f.seek(0)
test = f.readlines()
inventory = input("")

if "inv pick" in inventory: #Example "inv pick X"
    removeSpaces = inventory.split(" ")
    itemHolder = removeSpaces[2]
    final = itemHolder + "\n"
    f.write(final)

elif "inv drop" in inventory: #Example: "inv drop X"
    remove =  inventory.split(" ")
    itemHolder1 = remove[2]
    thefinal = itemHolder1 + "\n"
    test = test.remove(thefinal)

elif inventory == "inv": #Show inventory
    for i, item in enumerate(test):
        afterRemove = item.strip()
        print("{}. {}".format(i + 1, afterRemove))

f.close()

我已尝试在删除项的条件下写出列表，.remove函数正在工作，但删除项后文件未更新。我假设我必须在删除某些内容后写回该文件，但它不适用于：f.write(test)。有什么建议吗

谢谢