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python - 使用元的刮擦通行证值从未更新

发布于 2020-03-28 23:19:10

我正在尝试抓取一些网站。我已经获得了数据,并尝试使用传递值meta={}但是,当我使用yield scrapy.Request下一个功能,就会出现问题我被发送到下一个函数的是一个新的URL,并meta用于传递JSON值。我有新的URL,但没有JSON数据,JSON从未更新。刚刚传递了相同的值。我不知道是怎么回事。

您可以看到我的代码,我想传递JSON值,但是我只得到了相同的JSON,但URL随新URL一起更新。

def first_function(self, response):
    value_json = self.get_json() #i got the json from here
    for key, value in value_json.items(): #loop the json
        for values in value:

            # values will show me as dictionay of dictionary
            # thats like {"blabla":{"key1":"value1","key1":"value2"}}
            # I gave the conditions as below to get just a value or to make sure if that key ("blabla") is exist
            # if the condition is true, i will get the value {"key1":"value1","key1":"value2"}

            if values == "blabla":
                get_url = "http://www.example.com/"
                yield Request(
                    url=get_url+values["id_url"],
                    meta={"data_rest":values}, 
                    callback=self.second_function
                )

def second_function(self, response):
    # ============== PROBLEM =====================
    # The problem is here!
    # I always got a new url from first_function, my logic is if I got a new url, i should get a new json
    # but the json or "data_rest" never updated. Always send the same json to this function
    # ============== PROBLEM =====================

    josn_data = response.meta["data_rest"]
    names = response.css() #get the tag in here
    for get_data in names:
        sub_url = get_data.css("a::attr(href)").extract()
        for loop_url_menu in sub_url:
            yield scrapy.Request(
                url=loop_url_menu, 
                headers=self.session,
                meta = {
                    'dont_redirect': True,
                    'handle_httpstatus_list': [302]
                }, callback=self.next_function
            )

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提问者
Stefani Johnsson
被浏览
73
Stefani Johnsson 2020-01-31 17:25

好消息!!我可以解决的 我们只需要在第一个值后附加值,就可以生成该值。

def first_function(self, response):
    temp = []
    value_json = self.get_json() #i got the json from here
    for key, value in value_json.items(): #loop the json
        for values in value:
            if values == "blabla":
                get_url = "http://www.example.com/"
                temp.append(values)

    yield Request(
        url=get_url+values["id_url"],
        meta={"data_rest":temp}, 
        callback=self.second_function
    )