通过CrawlSpider对招聘网站进行整站爬取

数据表结构设计

建立数据表sql语句参考

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CREATE TABLE `article_spider`.`Untitled`  (
  `title` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `url` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `salary` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `job_city` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `work_years` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `degree_need` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `job_type` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `publish_time` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `job_advantage` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT '',
  `job_desc` longtext CHARACTER SET utf8 COLLATE utf8_general_ci NULL,
  `job_addr` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `company_url` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `company_name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `url_object_id` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `tags` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `crawl_time` datetime(0) NULL DEFAULT NULL,
  PRIMARY KEY (`url_object_id`) USING BTREE
) ENGINE = MyISAM CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

新建CrawlSpider与settings配置

进入虚拟环境后，新建CrawlSpider：

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scrapy genspider -t crawl lagou www.lagou.com

如果发现失败，需要进入settings.py引入路径

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import sys
BASE_DIR = os.path.dirname(os.path.abspath(os.path.dirname(__file__)))
sys.path.insert(0, os.path.join(BASE_DIR, 'ArticleSpider'))

拉勾网302之后的模拟登录和cookie传递

可以设置为适合自己的快捷键方式。
快捷键设置

selenium模拟登录后拿到cookie交给scrapy的request使用

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#lagou.py
    def start_requests(self):
        BASE_DIR = "C:/Users/yjw55/ArticleSpider/ArticleSpider"
        #去使用selenium模拟登录后拿到cookie交给scrapy的request使用
        # 通过selenium模拟登录
        #从文件中读取cookies
        cookies = []
        cookies = []
        from selenium import webdriver
        import time
        browser = webdriver.Chrome(executable_path="C:/Program Files (x86)/Google/Chrome/Application/chromedriver.exe")
        browser.get("https://passport.lagou.com/login/login.html")
        #判断文件是否存在
        if os.path.exists(BASE_DIR + "/cookies/lagou.cookie"):
            cookies = pickle.load(open(BASE_DIR + "/cookies/lagou.cookie", "rb"))
            for cookie in cookies:
                browser.add_cookie(cookie)
            browser.get("https://www.lagou.com/")

        if not cookies:
                browser.get("https://passport.lagou.com/login/login.html")
                browser.find_element_by_css_selector(".form_body .input_white").send_keys("1318")
                browser.find_element_by_css_selector('.form_body input[type="password"]').send_keys("me3")
                browser.find_element_by_css_selector('div[data-view="passwordLogin"] input.btn_lg').click()
                import time
                time.sleep(8)
                cookies = browser.get_cookies()
                # 写入cookie到文件中
                time.sleep(8)
               pickle.dump(cookies,open(BASE_DIR + "/cookies/lagou.cookie", "wb"))


        cookie_dict = {}
        for cookie in cookies:
            cookie_dict[cookie["name"]] = cookie["value"]

        #重写了，就要把之前它的逻辑拷贝一份
        for url in self.start_urls:
            yield scrapy.Request(url, dont_filter=True, cookies=cookie_dict)

settings.py设置全局COOKIES

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COOKIES_ENABLED = True
COOKIES_DEBUG = True

USER_AGENT = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; AcooBrowser; .NET CLR 1.1.4322; .NET CLR 2.0.50727)"

item loader方式解析职位

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# lagou.py
class LagouSpider(CrawlSpider):
    name = 'lagou'
    allowed_domains = ['www.lagou.com']
    start_urls = ['http://www.lagou.com/']

    rules = (
        Rule(LinkExtractor(allow=("zhaopin/.*",)), follow=True),
        Rule(LinkExtractor(allow=("gongsi/j\d+.html",)), follow=True),
        Rule(LinkExtractor(allow=r'jobs/\d+.html'), callback='parse_job', follow=True),
    )

    def parse_job(self, response):
        item_loader = LagouJobItemLoader(item=LagouJobItem(), response=response)
        item_loader = LagouJobItemLoader(item=LagouJobItem(), response=response)
        item_loader.add_css("title", ".job-name::attr(title)")
        item_loader.add_value("url", response.url)
        item_loader.add_value("url_object_id", get_md5(response.url))
        item_loader.add_css("salary", ".job_request .salary::text")
        item_loader.add_xpath("job_city", "//*[@class='job_request']//span[2]/text()")
        item_loader.add_xpath("work_years", "//*[@class='job_request']//span[3]/text()")
        item_loader.add_xpath("degree_need", "//*[@class='job_request']//span[4]/text()")
        item_loader.add_xpath("job_type", "//*[@class='job_request']//span[5]/text()")

        item_loader.add_css("tags", '.position-label li::text')
        item_loader.add_css("publish_time", ".publish_time::text")
        item_loader.add_css("job_advantage", ".job-advantage p::text")
        item_loader.add_css("job_desc", ".job_bt div")
        item_loader.add_css("job_addr", ".work_addr")
        item_loader.add_css("company_name", "#job_company dt a img::attr(alt)")
        item_loader.add_css("company_url", "#job_company dt a::attr(href)")
        item_loader.add_value("crawl_time", datetime.now())

        job_item = item_loader.load_item()
        return job_item

职位数据入库

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# items.py
from w3lib.html import remove_tags

def remove_splash(value):
    #去掉工作城市的斜线
    return value.replace("/","")

def handle_jobaddr(value):
    addr_list = value.split("\n")
    addr_list = [item.strip() for item in addr_list if item.strip()!="查看地图"]
    return "".join(addr_list)

class LagouJobItemLoader(ItemLoader):
    #自定义itemloader
    default_output_processor = TakeFirst()

class LagouJobItem(scrapy.Item):
    title = scrapy.Field()
    url = scrapy.Field()
    url_object_id = scrapy.Field()
    salary = scrapy.Field()
    job_city = scrapy.Field(
        #入库之前要执行的动作
        input_processor=MapCompose(remove_splash),
    )
    work_years = scrapy.Field(
        input_processor=MapCompose(remove_splash),
    )
    degree_need = scrapy.Field(
        input_processor=MapCompose(remove_splash),
    )
    job_type = scrapy.Field()
    publish_time = scrapy.Field()
    job_advantage = scrapy.Field()
    job_desc = scrapy.Field()
    job_addr = scrapy.Field(
        input_processor=MapCompose(remove_tags, handle_jobaddr),
    )
    company_name = scrapy.Field()
    company_url = scrapy.Field()
    tags = scrapy.Field(
        input_processor=Join(",")
    )

    crawl_time = scrapy.Field()

    def get_insert_sql(self):
        insert_sql = """
                insert into lagou_job(title, url, url_object_id, salary, job_city, work_years, degree_need,
                job_type, publish_time, job_advantage, job_desc, job_addr, company_name, company_url,
                tags, crawl_time) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
                ON DUPLICATE KEY UPDATE salary=VALUES(salary), job_desc=VALUES(job_desc)
            """
        params = (
            self.get("title", ""),
            self.get("url", ""),
            self.get("url_object_id", ""),
            self.get("salary", ""),
            self.get("job_city", ""),
            self.get("work_years", ""),
            self.get("degree_need", ""),
            self.get("job_type", ""),
            self.get("publish_time", "0000-00-00"),
            self.get("job_advantage", ""),
            self.get("job_desc", ""),
            self.get("job_addr", ""),
            self.get("company_name", ""),
            self.get("company_url", ""),
            self.get("job_addr", ""),
            self["crawl_time"].strftime(SQL_DATETIME_FORMAT),
        )

        return insert_sql, params

设置settings.py：

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ITEM_PIPELINES = {
    'ArticleSpider.pipelines.MysqlTwistedPipline': 4,
}
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#pipelines.py
class MysqlTwistedPipline(object):
    def __init__(self, dbpool):
        self.dbpool = dbpool

    @classmethod
    def from_settings(cls, settings):
        dbparms = dict(
            host = settings["MYSQL_HOST"],
            db = settings["MYSQL_DBNAME"],
            user = settings["MYSQL_USER"],
            passwd = settings["MYSQL_PASSWORD"],
            charset='utf8',
            cursorclass=MySQLdb.cursors.DictCursor,
            use_unicode=True,
        )
        dbpool = adbapi.ConnectionPool("MySQLdb", **dbparms)

        return cls(dbpool)

    def process_item(self, item, spider):
        #使用twisted将mysql插入变成异步执行
        query = self.dbpool.runInteraction(self.do_insert, item)
        query.addErrback(self.handle_error, item, spider) #处理异常
        return item

    def handle_error(self, failure, item, spider):
        #处理异步插入的异常
        print (failure)

    def do_insert(self, cursor, item):
        #执行具体的插入
        #根据不同的item 构建不同的sql语句并插入到mysql中
        insert_sql, params = item.get_insert_sql()
        cursor.execute(insert_sql, params)

网站反爬突破

RANDOMIZE_DOWNLOAD_DELAY：默认: True

如果启用，当从相同的网站获取数据时，Scrapy将会等待一个随机的值 (0.5到1.5之间的一个随机值 * DOWNLOAD_DELAY)。

该随机值降低了crawler被检测到(接着被block)的机会。某些网站会分析请求， 查找请求之间时间的相似性。

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#settings.py
DOWNLOAD_DELAY = 3
RANDOMIZE_DOWNLOAD_DELAY = True
Python
Python 爬虫

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