python - 2个列表之间的差异

Question

在输出列表中不在第二个列表中的项目时，我遇到以下问题。

这是代码:

def getInitialList(): # Define initial list with the use of requests and BS, will return a set

    getInHtml = requests.get("http://127.0.0.1")
    parseInHtml = BeautifulSoup(getInHtml.content, "html.parser")

    processInHtml = parseInHtml.find_all("div", class_="inner-article")

    firstList = []

    for items in processInHtml:
        firstList.append(items)

    return firstList

def getSecList(): #Define second list with the use of requests and BS, will return a set
    getHtml = requests.get("http://127.0.0.1")
    parseHtml = BeautifulSoup(getHtml.content, "html.parser")

    processHtml = parseHtml.find_all("div", class_="inner-article")

    secList = []

    for items in processHtml:
        secList.append(items)

    return secList

def catch_new_item():

    initList = getInitialList()

    while True:
        if initList == getSecList():
            print("No new items")
        else:
            print("New items found")
            break
    secList = getSecList()
    return set(secList) - set(initList)

最后一个函数(catch_new_items())应该返回 secList 中不在 initList 中的内容，但是当我运行它时，它返回一个空集。

地址 127.0.0.1 是一个本地 Web 服务器，我正在运行该服务器来确定这两个项目之间的差异。我所做的就是编辑 html 并向其中添加一个元素。

请告诉我你的想法？

Answer 1

我以这种方式修改了代码，以进行调试:

def getInitialList(): # Define initial list with the use of requests and BS, will return a set

    firstList = ['1', '2', '3']
    return firstList

def getSecList(): #Define second list with the use of requests and BS, will return a set

    secList = ['a', 'b', '3', '1']
    return secList

def catch_new_item():

    initList = getInitialList()
    while True:
        if initList == getSecList():
            print("No new items")
        else:
            print("New items found")
        break
    secList = getSecList()
    return set(secList) - set(initList)

print(catch_new_item())

它返回:

New items found
{'a'}

所以元素检测的逻辑是好的。

1. 您是否尝试过从 getInitialList() 打印出您的列表并 getSecList()函数看看是否为空？
2. 列表真的包含不同的项目吗？ (如果它们不为空，请参阅 p。 1)