一个爬取中国大学MOOC的爬虫

不知道什么时候写的了,发上来备份一下吧。

# -*- coding: utf-8 -*-
'''A simple spider fetching data from the url http://www.icourse163.org/search.htm.

@author: uchkks
@file: Spider.py
@time: 2020-2-27 23:47

'''
import requests
import urllib.parse
import json
import time
from typing import Union, Optional, Tuple

__all__ = [
    "urlencode",
    "urldecode",
    "CourseItem",
    "spider_page_by_index",
    "spider_all"
]

urlencode = urllib.parse.quote
urldecode = urllib.parse.unquote
UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36"


class CourseItem():
    """The item fetched in the website. Properties are the following:

    ``title``: The title of this course.
    ``photourl``: The url of this course photo.
    ``intro``: The introduction of this course.
    ``number``: The number of the students attending this course.
    ``courseurl``: The url of this course.

    """

    def __init__(self, title: str, photourl: str, intro: str, number: int, courseurl: str):
        self.title = title
        self.photourl = photourl
        self.intro = intro
        self.number = number
        self.courseurl = courseurl

    def __str__(self):
        return json.dumps(self.__dict__)

    def __repr__(self):
        return json.dumps(self.__dict__)


def newCourseItem(info: dict) -> Tuple[str, CourseItem]:
    """Create an instacne of CourseItem using the given ``info``(a ``dict``).

    Returns:
        A ``(str, CourseItem)`` will be returned. The first item is the ``courseid``
        (A format string, ``'{schoolid}-{courseid}'``), the second item is ``CourseItem.``
    """
    courseID = f'{info["schoolPanel"]["shortName"]}-{info["id"]}'
    title = info["name"]
    photourl = info["termPanel"]["bigPhotoUrl"]
    intro = info["termPanel"]["jsonContent"]
    number = info["termPanel"]["enrollCount"]
    courseurl = 'https://www.icourse163.org/course/' + courseID
    return courseID, CourseItem(title, photourl, intro, number, courseurl)


def spider_page_by_index(keyword: Union[str, bytes, bytearray],
                         pageindex: int = 1,
                         session: Optional[requests.Session] = None) -> dict:
    """Fetches data from the url www.icourse163.org/search.htm, using
    the given ``keyword`` and ``pageindex`` (optional) and returns a dict of result.

    Args:
        ``keyword``: must be a ``str``, ``bytes`` or ``bytearray`` instance, the keyword
        you want to lookup in the website.
        ``pageindex``: optional, an int, the current index of the page, default 1.
        ``session``: optional, an instance of requests.Session, if it is not provieded,
        a new session will be created.

    Returns:
        A ``dict`` containing search result will be returned.

    Raises:
        ``UnicodeError``: if keyword is a str and startwith the UTF-8 BOM '\ufeff', or
        the decode function cannot decode the bytes or bytearray correctly.
        ``TypeError``: if keyword is not an instance of str, bytes or bytearray, or
        pageindex is not an integer.
        ``RequestException``: an exception from module requests.exception, raises when
        an exception occurrs while handling a request.
    """
    if isinstance(keyword, str):
        if keyword.startswith('\ufeff'):
            raise UnicodeError("Unexpected UTF-8 BOM (decode using utf-8-sig)")
    else:
        if not isinstance(keyword, (bytes, bytearray)):
            raise TypeError(f'the keyword must be str, bytes or bytearray, '
                            f'not {keyword.__class__.__name__}')
        if not isinstance(pageindex, int):
            raise TypeError(f'the pageindex must be int, '
                            f'not {keyword.__class__.__name__}')
        keyword = keyword.decode()
    url = f"http://www.icourse163.org/search.htm?search={urlencode(keyword)}#/"
    if session == None:
        session = requests.Session()
        session.get(url=url, headers={"User-Agent": UserAgent})
    csrfKey = session.cookies["NTESSTUDYSI"]
    postbody = f'query={{"keyword":"{keyword}","pageIndex":{pageindex}' \
               ',"highlight":true,"orderBy":0,"stats":30,"pageSize":20}'
    headers = session.headers
    headers["edu-script-token"] = csrfKey
    headers["Host"] = "www.icourse163.org"
    headers["Origin"] = "http://www.icourse163.org"
    headers["Referer"] = url
    headers["Content-Type"] = "application/x-www-form-urlencoded"
    res = session.post("https://www.icourse163.org/web/j/mocSearchBean.searchMocCourse.rpc"
                       f"?csrfKey={csrfKey}", data=postbody.encode(), headers=headers)
    text = res.text
    resultmap = json.loads(text)
    return resultmap


def spider_all(keyword: Union[str, bytes, bytearray]) -> dict:
    """Fetches data from the url www.icourse163.org/search.htm, using
    the given ``keyword`` and returns a dict of result.

    Args:
        ``keyword``: must be a ``str``, ``bytes`` or ``bytearray`` instance, the keyword
        you want to lookup in the website.

    Returns:
        A ``dict`` containing search result will be returned.

    Raises:
        ``UnicodeError``: if keyword is a str and startwith the UTF-8 BOM '\ufeff', or
        the decode function cannot decode the bytes or bytearray.
        ``TypeError``: if keyword is not an instance of str, bytes or bytearray.
        ``ValueError``: if fetching fails.
        ``RequestException``: an exception from module requests.exception, raises when
        an exception occurrs while handling a request.
    """
    session = requests.Session()
    url = f"http://www.icourse163.org/search.htm?search={urlencode(keyword)}#/"
    session.get(url=url, headers={"User-Agent": UserAgent})
    resultmap = spider_page_by_index(keyword, session=session)
    if resultmap["result"] == None:
        raise ValueError(f"The result map is not valid. The error message is {resultmap['message']}")
    resultmap = resultmap["result"]
    totlePageCount = resultmap["pagination"]["totlePageCount"] + 1
    result = {}
    for info in resultmap["result"]:
        courseID, course = newCourseItem(info["mocCourseCardDto"])
        result[courseID] = course
    for pageindex in range(2, totlePageCount):
        time.sleep(1)
        resultmap = spider_page_by_index(keyword, pageindex=pageindex, session=session)
        if resultmap["result"] == None:
            raise ValueError(f"The result map is not valid. The error message is {resultmap['message']}")
        resultmap = resultmap["result"]
        for info in resultmap["result"]:
            courseID, course = newCourseItem(info["mocCourseCardDto"])
            result[courseID] = course
    # print(result)
    return result


if __name__ == "__main__":
    print(spider_all("Python"))
©著作权归作者所有,转载或内容合作请联系作者
  • 序言:七十年代末,一起剥皮案震惊了整个滨河市,随后出现的几起案子,更是在滨河造成了极大的恐慌,老刑警刘岩,带你破解...
    沈念sama阅读 214,172评论 6 493
  • 序言:滨河连续发生了三起死亡事件,死亡现场离奇诡异,居然都是意外死亡,警方通过查阅死者的电脑和手机,发现死者居然都...
    沈念sama阅读 91,346评论 3 389
  • 文/潘晓璐 我一进店门,熙熙楼的掌柜王于贵愁眉苦脸地迎上来,“玉大人,你说我怎么就摊上这事。” “怎么了?”我有些...
    开封第一讲书人阅读 159,788评论 0 349
  • 文/不坏的土叔 我叫张陵,是天一观的道长。 经常有香客问我,道长,这世上最难降的妖魔是什么? 我笑而不...
    开封第一讲书人阅读 57,299评论 1 288
  • 正文 为了忘掉前任,我火速办了婚礼,结果婚礼上,老公的妹妹穿的比我还像新娘。我一直安慰自己,他们只是感情好,可当我...
    茶点故事阅读 66,409评论 6 386
  • 文/花漫 我一把揭开白布。 她就那样静静地躺着,像睡着了一般。 火红的嫁衣衬着肌肤如雪。 梳的纹丝不乱的头发上,一...
    开封第一讲书人阅读 50,467评论 1 292
  • 那天,我揣着相机与录音,去河边找鬼。 笑死,一个胖子当着我的面吹牛,可吹牛的内容都是我干的。 我是一名探鬼主播,决...
    沈念sama阅读 39,476评论 3 412
  • 文/苍兰香墨 我猛地睁开眼,长吁一口气:“原来是场噩梦啊……” “哼!你这毒妇竟也来了?” 一声冷哼从身侧响起,我...
    开封第一讲书人阅读 38,262评论 0 269
  • 序言:老挝万荣一对情侣失踪,失踪者是张志新(化名)和其女友刘颖,没想到半个月后,有当地人在树林里发现了一具尸体,经...
    沈念sama阅读 44,699评论 1 307
  • 正文 独居荒郊野岭守林人离奇死亡,尸身上长有42处带血的脓包…… 初始之章·张勋 以下内容为张勋视角 年9月15日...
    茶点故事阅读 36,994评论 2 328
  • 正文 我和宋清朗相恋三年,在试婚纱的时候发现自己被绿了。 大学时的朋友给我发了我未婚夫和他白月光在一起吃饭的照片。...
    茶点故事阅读 39,167评论 1 343
  • 序言:一个原本活蹦乱跳的男人离奇死亡,死状恐怖,灵堂内的尸体忽然破棺而出,到底是诈尸还是另有隐情,我是刑警宁泽,带...
    沈念sama阅读 34,827评论 4 337
  • 正文 年R本政府宣布,位于F岛的核电站,受9级特大地震影响,放射性物质发生泄漏。R本人自食恶果不足惜,却给世界环境...
    茶点故事阅读 40,499评论 3 322
  • 文/蒙蒙 一、第九天 我趴在偏房一处隐蔽的房顶上张望。 院中可真热闹,春花似锦、人声如沸。这庄子的主人今日做“春日...
    开封第一讲书人阅读 31,149评论 0 21
  • 文/苍兰香墨 我抬头看了看天上的太阳。三九已至,却和暖如春,着一层夹袄步出监牢的瞬间,已是汗流浃背。 一阵脚步声响...
    开封第一讲书人阅读 32,387评论 1 267
  • 我被黑心中介骗来泰国打工, 没想到刚下飞机就差点儿被人妖公主榨干…… 1. 我叫王不留,地道东北人。 一个月前我还...
    沈念sama阅读 47,028评论 2 365
  • 正文 我出身青楼,却偏偏与公主长得像,于是被迫代替她去往敌国和亲。 传闻我的和亲对象是个残疾皇子,可洞房花烛夜当晚...
    茶点故事阅读 44,055评论 2 352

推荐阅读更多精彩内容