MediaCrawler/media_platform/zhihu/help.py

# 声明：本代码仅供学习和研究目的使用。使用者应遵守以下原则：  
# 1. 不得用于任何商业用途。  
# 2. 使用时应遵守目标平台的使用条款和robots.txt规则。  
# 3. 不得进行大规模爬取或对平台造成运营干扰。  
# 4. 应合理控制请求频率，避免给目标平台带来不必要的负担。   
# 5. 不得用于任何非法或不当的用途。
#   
# 详细许可条款请参阅项目根目录下的LICENSE文件。  
# 使用本代码即表示您同意遵守上述原则和LICENSE中的所有条款。  


# -*- coding: utf-8 -*-
import json
from typing import Dict, List, Optional
from urllib.parse import parse_qs, urlparse

import execjs
from parsel import Selector

from constant import zhihu as zhihu_constant
from model.m_zhihu import ZhihuComment, ZhihuContent, ZhihuCreator
from tools.crawler_util import extract_text_from_html

ZHIHU_SGIN_JS = None


def sign(url: str, cookies: str) -> Dict:
    """
    zhihu sign algorithm
    Args:
        url: request url with query string
        cookies: request cookies with d_c0 key

    Returns:

    """
    global ZHIHU_SGIN_JS
    if not ZHIHU_SGIN_JS:
        with open("libs/zhihu.js", mode="r", encoding="utf-8-sig") as f:
            ZHIHU_SGIN_JS = execjs.compile(f.read())

    return ZHIHU_SGIN_JS.call("get_sign", url, cookies)


class ZhihuExtractor:
    def __init__(self):
        pass

    def extract_contents_from_search(self, json_data: Dict) -> List[ZhihuContent]:
        """
        extract zhihu contents
        Args:
            json_data: zhihu json data

        Returns:

        """
        if not json_data:
            return []

        search_result: List[Dict] = json_data.get("data", [])
        search_result = [s_item for s_item in search_result if s_item.get("type") in ['search_result', 'zvideo']]
        return self._extract_content_list([sr_item.get("object") for sr_item in search_result if sr_item.get("object")])


    def _extract_content_list(self, content_list: List[Dict]) -> List[ZhihuContent]:
        """
        extract zhihu content list
        Args:
            content_list:

        Returns:

        """
        if not content_list:
            return []

        res: List[ZhihuContent] = []
        for content in content_list:
            if content.get("type") == zhihu_constant.ANSWER_NAME:
                res.append(self._extract_answer_content(content))
            elif content.get("type") == zhihu_constant.ARTICLE_NAME:
                res.append(self._extract_article_content(content))
            elif content.get("type") == zhihu_constant.VIDEO_NAME:
                res.append(self._extract_zvideo_content(content))
            else:
                continue
        return res

    def _extract_answer_content(self, answer: Dict) -> ZhihuContent:
        """
        extract zhihu answer content
        Args:
            answer: zhihu answer

        Returns:
        """
        res = ZhihuContent()
        res.content_id = answer.get("id")
        res.content_type = answer.get("type")
        res.content_text = extract_text_from_html(answer.get("content", ""))
        res.question_id = answer.get("question").get("id")
        res.content_url = f"{zhihu_constant.ZHIHU_URL}/question/{res.question_id}/answer/{res.content_id}"
        res.title = extract_text_from_html(answer.get("title", ""))
        res.desc = extract_text_from_html(answer.get("description", "") or answer.get("excerpt", ""))
        res.created_time = answer.get("created_time")
        res.updated_time = answer.get("updated_time")
        res.voteup_count = answer.get("voteup_count", 0)
        res.comment_count = answer.get("comment_count", 0)

        # extract author info
        author_info = self._extract_content_or_comment_author(answer.get("author"))
        res.user_id = author_info.user_id
        res.user_link = author_info.user_link
        res.user_nickname = author_info.user_nickname
        res.user_avatar = author_info.user_avatar
        res.user_url_token = author_info.url_token
        return res

    def _extract_article_content(self, article: Dict) -> ZhihuContent:
        """
        extract zhihu article content
        Args:
            article: zhihu article

        Returns:

        """
        res = ZhihuContent()
        res.content_id = article.get("id")
        res.content_type = article.get("type")
        res.content_text = extract_text_from_html(article.get("content"))
        res.content_url = f"{zhihu_constant.ZHIHU_URL}/p/{res.content_id}"
        res.title = extract_text_from_html(article.get("title"))
        res.desc = extract_text_from_html(article.get("excerpt"))
        res.created_time = article.get("created_time", 0) or article.get("created", 0)
        res.updated_time = article.get("updated_time", 0) or article.get("updated", 0)
        res.voteup_count = article.get("voteup_count", 0)
        res.comment_count = article.get("comment_count", 0)

        # extract author info
        author_info = self._extract_content_or_comment_author(article.get("author"))
        res.user_id = author_info.user_id
        res.user_link = author_info.user_link
        res.user_nickname = author_info.user_nickname
        res.user_avatar = author_info.user_avatar
        res.user_url_token = author_info.url_token
        return res

    def _extract_zvideo_content(self, zvideo: Dict) -> ZhihuContent:
        """
        extract zhihu zvideo content
        Args:
            zvideo:

        Returns:

        """
        res = ZhihuContent()

        if "video" in zvideo and isinstance(zvideo.get("video"), dict): # 说明是从创作者主页的视频列表接口来的
            res.content_id = zvideo.get("video").get("video_id")
            res.content_url = f"{zhihu_constant.ZHIHU_URL}/zvideo/{res.content_id}"
            res.created_time = zvideo.get("published_at")
            res.updated_time = zvideo.get("updated_at")
        else:
            res.content_id = zvideo.get("zvideo_id")
            res.content_url = zvideo.get("video_url")
            res.created_time = zvideo.get("created_at")

        res.content_type = zvideo.get("type")
        res.title = extract_text_from_html(zvideo.get("title"))
        res.desc = extract_text_from_html(zvideo.get("description"))
        res.voteup_count = zvideo.get("voteup_count")
        res.comment_count = zvideo.get("comment_count")

        # extract author info
        author_info = self._extract_content_or_comment_author(zvideo.get("author"))
        res.user_id = author_info.user_id
        res.user_link = author_info.user_link
        res.user_nickname = author_info.user_nickname
        res.user_avatar = author_info.user_avatar
        res.user_url_token = author_info.url_token
        return res

    @staticmethod
    def _extract_content_or_comment_author(author: Dict) -> ZhihuCreator:
        """
        extract zhihu author
        Args:
            author:

        Returns:

        """
        res = ZhihuCreator()
        if not author:
            return res
        if not author.get("id"):
            author = author.get("member")
        res.user_id = author.get("id")
        res.user_link = f"{zhihu_constant.ZHIHU_URL}/people/{author.get('url_token')}"
        res.user_nickname = author.get("name")
        res.user_avatar = author.get("avatar_url")
        res.url_token = author.get("url_token")
        return res

    def extract_comments(self, page_content: ZhihuContent, comments: List[Dict]) -> List[ZhihuComment]:
        """
        extract zhihu comments
        Args:
            page_content: zhihu content object
            comments: zhihu comments

        Returns:

        """
        if not comments:
            return []
        res: List[ZhihuComment] = []
        for comment in comments:
            if comment.get("type") != "comment":
                continue
            res.append(self._extract_comment(page_content, comment))
        return res

    def _extract_comment(self, page_content: ZhihuContent, comment: Dict) -> ZhihuComment:
        """
        extract zhihu comment
        Args:
            page_content: comment with content object
            comment: zhihu comment

        Returns:

        """
        res = ZhihuComment()
        res.comment_id = str(comment.get("id", ""))
        res.parent_comment_id = comment.get("reply_comment_id")
        res.content = extract_text_from_html(comment.get("content"))
        res.publish_time = comment.get("created_time")
        res.ip_location = self._extract_comment_ip_location(comment.get("comment_tag", []))
        res.sub_comment_count = comment.get("child_comment_count")
        res.like_count = comment.get("like_count") if comment.get("like_count") else 0
        res.dislike_count = comment.get("dislike_count") if comment.get("dislike_count") else 0
        res.content_id = page_content.content_id
        res.content_type = page_content.content_type

        # extract author info
        author_info = self._extract_content_or_comment_author(comment.get("author"))
        res.user_id = author_info.user_id
        res.user_link = author_info.user_link
        res.user_nickname = author_info.user_nickname
        res.user_avatar = author_info.user_avatar
        return res

    @staticmethod
    def _extract_comment_ip_location(comment_tags: List[Dict]) -> str:
        """
        extract comment ip location
        Args:
            comment_tags:

        Returns:

        """
        if not comment_tags:
            return ""

        for ct in comment_tags:
            if ct.get("type") == "ip_info":
                return ct.get("text")

        return ""

    @staticmethod
    def extract_offset(paging_info: Dict) -> str:
        """
        extract offset
        Args:
            paging_info:

        Returns:

        """
        # https://www.zhihu.com/api/v4/comment_v5/zvideos/1424368906836807681/root_comment?limit=10&offset=456770961_10125996085_0&order_by=score
        next_url = paging_info.get("next")
        if not next_url:
            return ""

        parsed_url = urlparse(next_url)
        query_params = parse_qs(parsed_url.query)
        offset = query_params.get('offset', [""])[0]
        return offset

    @staticmethod
    def _foramt_gender_text(gender: int) -> str:
        """
        format gender text
        Args:
            gender:

        Returns:

        """
        if gender == 1:
            return "男"
        elif gender == 0:
            return "女"
        else:
            return "未知"


    def extract_creator(self, user_url_token: str, html_content: str) -> Optional[ZhihuCreator]:
        """
        extract zhihu creator
        Args:
            user_url_token : zhihu creator url token
            html_content: zhihu creator html content

        Returns:

        """
        if not html_content:
            return None

        js_init_data = Selector(text=html_content).xpath("//script[@id='js-initialData']/text()").get(default="").strip()
        if not js_init_data:
            return None

        js_init_data_dict: Dict = json.loads(js_init_data)
        users_info: Dict = js_init_data_dict.get("initialState", {}).get("entities", {}).get("users", {})
        if not users_info:
            return None

        creator_info: Dict = users_info.get(user_url_token)
        if not creator_info:
            return None

        res = ZhihuCreator()
        res.user_id = creator_info.get("id")
        res.user_link = f"{zhihu_constant.ZHIHU_URL}/people/{user_url_token}"
        res.user_nickname = creator_info.get("name")
        res.user_avatar = creator_info.get("avatarUrl")
        res.url_token = creator_info.get("urlToken") or user_url_token
        res.gender = self._foramt_gender_text(creator_info.get("gender"))
        res.ip_location = creator_info.get("ipInfo")
        res.follows = creator_info.get("followingCount")
        res.fans = creator_info.get("followerCount")
        res.anwser_count = creator_info.get("answerCount")
        res.video_count = creator_info.get("zvideoCount")
        res.question_count = creator_info.get("questionCount")
        res.article_count = creator_info.get("articlesCount")
        res.column_count = creator_info.get("columnsCount")
        res.get_voteup_count = creator_info.get("voteupCount")
        return res


    def extract_content_list_from_creator(self, anwser_list: List[Dict]) -> List[ZhihuContent]:
        """
        extract content list from creator
        Args:
            anwser_list:

        Returns:

        """
        if not anwser_list:
            return []

        return self._extract_content_list(anwser_list)