python scrapy爬取前程无忧招聘信息

使用scrapy框架之前，使用以下命令下载库：

pip install scrapy -i https://pypi.tuna.tsinghua.edu.cn/simple

1、创建项目文件夹

scrapy startproject 项目名

2、用pyCharm查看生成的项目目录

项目创建成功之后，会得到图中的文件目录

3、创建爬虫

根据提示cd到创建的项目文件中

使用以下命令创建爬虫

说明：

　　51_job.com ---- ----主域名

scrapy genspider spider_51_job 51job.com

此时，文件中多出了一个py文件

4、spider_51_job.py（代码）

说明：

from ..items import Scrapy51JobCrawlItem  ---- -----调用存储类（存储类代码会在后面呈现）

# -*- coding: utf-8 -*-
import scrapy
from ..items import Scrapy51JobCrawlItem


class QianPcSpider(scrapy.Spider):
    name = '51job_crawl'
    allowed_domains = ['51job.com']
    url = 'https://search.51job.com/list/000000,000000,0000,00,9,99,python,2,%s.html?'
    
    #循环获取网页链接
    a = []
    for i in range(1, 5):
        urls = url % i
        a.append(urls)
    start_urls = a

    def parse(self, response):
        #获取职位名称
        title_list = response.xpath('//div[@class="el"]/p/span/a')
        for i in title_list:
            # 职位href
            page_url = i.xpath('./@href').get()
            # 如果href存在，则回调执行函数item
            if page_url:
                yield scrapy.Request(page_url, callback=self.item)

    def item(self, response):
        """使用定义好的类"""
        data_list = Scrapy51JobCrawlItem()
        data_list['title'] = response.xpath('//div[@class="cn"]/h1/@title').get()   #职位名称
        data_list['salary'] = response.xpath('//div[@class="cn"]/strong/text()').get()  #职位工资
        data_list['company'] = response.xpath('//div[@class="cn"]/p/a/@title').get()    #公司名称
        data_list['Work_address'] = response.xpath('//div[@class="bmsg inbox"]/p/text()').get() #工作地址
        yield data_list

5、定义存储类　

items.py（代码）

# -*- coding: utf-8 -*-
# Define here the models for your scraped items
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/items.html

import scrapy

class Scrapy51JobCrawlItem(scrapy.Item):
    # 职位名称
    title = scrapy.Field()
    # 职位工资
    salary = scrapy.Field()
    # 公司名称
    company = scrapy.Field()
    # 工作地址
    Work_address = scrapy.Field()

6、管道相关代码

pipelines.py（代码）

# -*- coding: utf-8 -*-

# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html
# from flask import json
# from .items import Scrapy51JobCrawlItem
import json
from .items import Scrapy51JobCrawlItem

class QcwyPipeline(object):
    def process_item(self, item, spider):
        return item

class ScrapyDemoPipelin(object):
    def open_spider(self, spider):
        self.file = open('51_job.csv', 'w')

    def process_item(self, item, spider):
        if isinstance(item,Scrapy51JobCrawlItem):
            # 1.item - dict
            dict_data = dict(item)
            # 2.dict --str
            str_data = json.dumps(dict_data) + '
'
            # 3.写入文件
            self.file.write(str_data)

        return item

    def close_spider(self, spider):
        self.file.close()

修改完成之后，要在setting中开启管道（管道默认是关闭的）

7、在项目中创建一个main.py 启动文件

下面是相关代码：

# 项目启动文件
from scrapy import cmdline
cmdline.execute("scrapy crawl 51job_crawl".split())

代码运行成功后并没有我们想要的数据，我们只需要在setting中设置一个请求头即可

# Override the default request headers:
DEFAULT_REQUEST_HEADERS = {
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
    "Accept-Encoding": "gzip, deflate, br",
    "Accept-Language": "zh-CN,zh;q=0.9",
    "Cache-Control": "max-age=0",
    "Connection": "keep-alive",
    "Cookie": "guid=a314b28b83cee821d850c2f4aec4c17f; adv=adsnew%3D1%26%7C%26adsresume%3D1%26%7C%26adsfrom%3Dhttps%253A%252F%252Fsp0.baidu.com%252F9q9JcDHa2gU2pMbgoY3K%252Fadrc.php%253Ft%253D06KL00c00fDewkY03lV-00uiAsjsUOkI00000F2YH7C00000Im6S0g.THLZ_Q5n1VeHksK85HcdnjDLnjc1g1uxTAT0T1dBnjRknH79uj0snhPhryDk0ZRqfYF7rj61wHmzfHT3rDfvnjn4n1IKfRDLfH04PYuAPHD0mHdL5iuVmv-b5HnzrHfdPjTvrHDhTZFEuA-b5HDv0ARqpZwYTZnlQzqYTh7Wui3dnyGEmB4WUvYEIZF9mvR8TA9s5v7bTv4dUHYznj0YnW6zFh7JTjd9i7csmY9PPbk4rgw9nd7dH-wATyczigNunW-YHjPiUbs1HhkBR1-Luys3XRdDwHwnUy6sm-ILQdG8iMuBNj7GyNI_pvwmfWmhp1Y1PhRsPHw9mH0YPH-WnhNbujNBPjIhPHIWmWmknAf3n6KWThnqn1RzPW6%2526tpl%253Dtpl_11534_20937_16032%2526l%253D1514976402%2526attach%253Dlocation%25253D%252526linkName%25253D%252525E6%252525A0%25252587%252525E5%25252587%25252586%252525E5%252525A4%252525B4%252525E9%25252583%252525A8-%252525E6%252525A0%25252587%252525E9%252525A2%25252598-%252525E4%252525B8%252525BB%252525E6%252525A0%25252587%252525E9%252525A2%25252598%252526linkText%25253D%252525E3%25252580%25252590%252525E5%25252589%2525258D%252525E7%252525A8%2525258B%252525E6%25252597%252525A0%252525E5%252525BF%252525A751Job%252525E3%25252580%25252591-%25252520%252525E5%252525A5%252525BD%252525E5%252525B7%252525A5%252525E4%252525BD%2525259C%252525E5%252525B0%252525BD%252525E5%2525259C%252525A8%252525E5%25252589%2525258D%252525E7%252525A8%2525258B%252525E6%25252597%252525A0%252525E5%252525BF%252525A7%2521%252526xp%25253Did%2528%25252522m3294547691_canvas%25252522%2529%2525252FDIV%2525255B1%2525255D%2525252FDIV%2525255B1%2525255D%2525252FDIV%2525255B1%2525255D%2525252FDIV%2525255B1%2525255D%2525252FDIV%2525255B1%2525255D%2525252FH2%2525255B1%2525255D%2525252FA%2525255B1%2525255D%252526linkType%25253D%252526checksum%25253D78%2526ie%253Dutf-8%2526f%253D8%2526tn%253D25017023_6_pg%2526wd%253D%2525E5%252589%25258D%2525E7%2525A8%25258B%2525E6%252597%2525A0%2525E5%2525BF%2525A7%2526oq%253D%2525E5%252589%25258D%2525E7%2525A8%25258B%2525E6%252597%2525A0%2525E5%2525BF%2525A7%2526rqlang%253Dcn%2526lm%253D-1%2526ssl_s%253D1%2526ssl_c%253Dssl1_16f22154dbf%26%7C%26adsnum%3D2004282; nsearch=jobarea%3D%26%7C%26ord_field%3D%26%7C%26recentSearch0%3D%26%7C%26recentSearch1%3D%26%7C%26recentSearch2%3D%26%7C%26recentSearch3%3D%26%7C%26recentSearch4%3D%26%7C%26collapse_expansion%3D; 51job=cenglish%3D0%26%7C%26; search=jobarea%7E%60000000%7C%21ord_field%7E%600%7C%21recentSearch0%7E%60000000%A1%FB%A1%FA000000%A1%FB%A1%FA0000%A1%FB%A1%FA00%A1%FB%A1%FA99%A1%FB%A1%FA%A1%FB%A1%FA99%A1%FB%A1%FA99%A1%FB%A1%FA99%A1%FB%A1%FA99%A1%FB%A1%FA9%A1%FB%A1%FA99%A1%FB%A1%FA%A1%FB%A1%FA0%A1%FB%A1%FApython%A1%FB%A1%FA2%A1%FB%A1%FA1%7C%21recentSearch1%7E%60000000%A1%FB%A1%FA000000%A1%FB%A1%FA0000%A1%FB%A1%FA00%A1%FB%A1%FA99%A1%FB%A1%FA%A1%FB%A1%FA99%A1%FB%A1%FA99%A1%FB%A1%FA99%A1%FB%A1%FA99%A1%FB%A1%FA9%A1%FB%A1%FA99%A1%FB%A1%FA%A1%FB%A1%FA0%A1%FB%A1%FA%A1%FB%A1%FA2%A1%FB%A1%FA1%7C%21",
    "Host": "jobs.51job.com",
    "Referer": "https://search.51job.com/list/000000,000000,0000,00,9,99,python,2,1.html?",
    "Sec-Fetch-Mode": "navigate",
    "Sec-Fetch-Site": "same-site",
    "Sec-Fetch-User": "?1",
    "Upgrade-Insecure-Requests": "1",
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36",
}