进程池爬取并存入mongodb

设置进程池爬取拉钩网：

# coding = utf-8
import json
import pymongo
import pandas as pd
import requests
from lxml import etree
import time
from multiprocessing import Pool


# 设置mongodb
client = pymongo.MongoClient('localhost')
db = client['lagou']
# 查询的岗位名称
POSITION_NAME = '数据挖掘'
# 想要爬取的总页面数
PAGE_SUM = 200
# 每页返回的职位数量
PAGE_SIZE = 15
# 指定数据库的名字
DATA_NAME = "DataMiningPosition"


base_url = 'https://m.lagou.com/search.json?city=%E5%85%A8%E5%9B%BD&positionName={positionName}' 
           '&pageNo={pageNo}&pageSize={pageSize}'


def page_index(pageno):
    headers = {
        "Accept": "application/json",
        "Accept-Encoding": "gzip, deflate",
        "Accept-Language": "zh-CN,zh;q=0.9",
        # cookie能不要尽量不要，这里正好不用cookie也可以正常返回数据
        # "Cookie": "user_trace_token=20181119151914-03711263-38a2-4d81-bd81-5f480d930039; _ga=GA1.2.605262108.1542611954; _gid=GA1.2.249787972.1542611954; LGSID=20181119151916-6c3da9fa-ebcb-11e8-8958-5254005c3644; PRE_UTM=; PRE_HOST=www.baidu.com; PRE_SITE=https%3A%2F%2Fwww.baidu.com%2Flink%3Furl%3DOnHWjpEfiW4_pVm7hX8NYOFm0iJ7bz1ZJJlaKPPnmMzLE-6ypKNo0f19ABO5bjW4%26wd%3D%26eqid%3D8f61629100016e18000000065bf263e7; PRE_LAND=https%3A%2F%2Fwww.lagou.com%2Fgongsi%2F147.html; LGUID=20181119151916-6c3dabf3-ebcb-11e8-8958-5254005c3644; index_location_city=%E5%85%A8%E5%9B%BD; JSESSIONID=ABAAABAAAGCABCC2D851CA25D1CFCD2B28DCDD6E00A2C7E; _ga=GA1.3.605262108.1542611954; X_HTTP_TOKEN=a0cc1a4beb8a41f57f144bc0bfd77bd7; sajssdk_2015_cross_new_user=1; sensorsdata2015jssdkcross=%7B%22distinct_id%22%3A%221672adb3834203-08b3706084b44a-3961430f-1327104-1672adb3835428%22%2C%22%24device_id%22%3A%221672adb3834203-08b3706084b44a-3961430f-1327104-1672adb3835428%22%2C%22props%22%3A%7B%22%24latest_traffic_source_type%22%3A%22%E7%9B%B4%E6%8E%A5%E6%B5%81%E9%87%8F%22%2C%22%24latest_referrer%22%3A%22%22%2C%22%24latest_referrer_host%22%3A%22%22%2C%22%24latest_search_keyword%22%3A%22%E6%9C%AA%E5%8F%96%E5%88%B0%E5%80%BC_%E7%9B%B4%E6%8E%A5%E6%89%93%E5%BC%80%22%7D%7D; Hm_lvt_4233e74dff0ae5bd0a3d81c6ccf756e6=1542611954,1542612053,1542612277,1542612493; _gat=1; Hm_lpvt_4233e74dff0ae5bd0a3d81c6ccf756e6=1542613115; LGRID=20181119153837-20bafb1a-ebce-11e8-8958-5254005c3644",
        "Host": "m.lagou.com",
        "Proxy-Connection": "keep-alive",
        "Referer": "http://m.lagou.com/search.html",
        "X-Requested-With": "XMLHttpRequest",
        'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) '
                      'Chrome/45.0.2454.85 Safari/537.36 115Browser/6.0.3',
    }
    url = base_url.format(positionName=POSITION_NAME, pageNo=pageno, pageSize=PAGE_SIZE)
    response = requests.get(url, headers=headers)
    html = response.text
    content = json.loads(html)
    print(content)
    if content.get("content"):
        return content
    else:
        time.sleep(30)
        return page_index(pageno)


def parse_page_index(content):
    
    for i in range(15):
        try:
            item = content['content']['data']['page']['result'][i]
            #print(item)
            yield {
                'positionId': item.get('positionId'),
                'positionName': item.get('positionName'),
                'city': item.get('city'),
                'createTime': item.get('createTime'),
                'salary': item.get('salary'),
                'companyId': item.get('companyId'),
                'companyFullName': item.get('companyFullName')
            }
        except IndexError as e:
            print('可能没有那么多字段', e)

def save_to_mongo(data):
    if db[DATA_NAME].update({'positionId': data['positionId']}, {'$set': data}, True):
        print('Saved to Mongo', data['positionId'])
    else:
        print('Saved to Mongo Failed', data['positionId'])

def parse_detail(url):
    # url = "http://m.lagou.com/jobs/4593934.html"
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.140 Safari/537.36",
        "Accept": "text / html, application / xhtml + xml, application / xml;q = 0.9, image / webp, image / apng, * / *;q = 0.8",
        "Accept - Encoding": "gzip, deflate",
        "Accept - Language": "zh - CN, zh;q = 0.9",
        "Cache - Control": "max - age = 0",
        "Connection": "eep - alive",
       # "Cookie": "_ga=GA1.2.474762156.1528795210; _gid=GA1.2.574638607.1528795210; user_trace_token=20180612172010-cdf76dc1-6e21-11e8-9af0-525400f775ce; LGUID=20180612172010-cdf772c0-6e21-11e8-9af0-525400f775ce; Hm_lvt_4233e74dff0ae5bd0a3d81c6ccf756e6=1528795210,1528795215,1528795223; index_location_city=%E5%85%A8%E5%9B%BD; X_HTTP_TOKEN=f3ed266ddeee802fb7d402e4f6d4f4a3; JSESSIONID=ABAAABAAAFDABFG9F9C52FA9D8CAE24F139A0131C45E918; _ga=GA1.3.474762156.1528795210; _gat=1; LGSID=20180612184248-597a7795-6e2d-11e8-9479-5254005c3644; PRE_UTM=; PRE_HOST=; PRE_SITE=http%3A%2F%2Fm.lagou.com%2Fsearch.html; PRE_LAND=http%3A%2F%2Fm.lagou.com%2Fjobs%2F4079910.html; LGRID=20180612184505-ab051d02-6e2d-11e8-9479-5254005c3644; Hm_lpvt_4233e74dff0ae5bd0a3d81c6ccf756e6=1528800306"
    
    }
    try:
        response = requests.get(url, headers=headers)
        if response.status_code == 200:
            print("请求成功")
            text = response.content.decode()
            # print(text)
            html = etree.HTML(text)
            workyear = html.xpath('//span[@class="item workyear"]/span/text()')
            if workyear:
                workyear = workyear[0]
            else:
                time.sleep(5)
                parse_detail(url)
            positiondesc = html.xpath('//div[@class="positiondesc"]//p/text()')
            #print(workyear, positiondesc)
            return workyear, positiondesc
    except Exception as e:
        print(e)

# 将爬取的数据存到Mongodb
def to_mongo(page_sum):
    # 拉勾网顶多只能显示到334页
    for page in range(page_sum):
        html = page_index(page)
        items = parse_page_index(html)
        # print(items)
        for item in items:
            print(item)
            save_to_mongo(item)

# 运用进程池将爬取的数据存到Mongodb
def to_mongo_pool(page):
    # 拉勾网顶多只能显示到334页
    content = page_index(page)
    items = parse_page_index(content)
    # print(items)
    for item in items:
        print(item)
        save_to_mongo(item)


# 解析爬取的字条，以便把数据转为DataFrame格式
def parse_items(page_sum):
    for page in range(page_sum):
        html = page_index(page)
        items = parse_page_index(html)
        for item in items:
            positionId = item["positionId"]
            detail_url = "http://m.lagou.com/jobs/{}.html".format(positionId)
            workyear, positiondesc = parse_detail(detail_url)
            print(positionId,positiondesc)
            yield [
                item["positionId"],
                item["positionName"],
                item["city"],
                item["createTime"],
                item["salary"],
                item["companyId"],
                item["companyFullName"],
                workyear,
                positiondesc
            ]

# 把数据保存为csv格式
def to_csv(page_sum):
    item_lists = []
    # print(parse_items())
    for item in parse_items(page_sum):
        item_lists.append(item)
    #print(item_lists)
    data = pd.DataFrame(item_lists,
                        columns=["positionId", "positionName", "city", "createTime", "salary", "companyId",
                                 "companyFullName", "workyear", "positiondesc"])
    data.to_csv("python_positon.csv")

if __name__ == '__main__':
    
    #to_csv
    #to_mongo(200)
    #  建议保存到mongodb数据库中

    start_time = time.time()
    pool = Pool()  # pool()参数：进程个数：默认的是电脑cpu的核的个数，如果要指定进程个数，这个进程个数要小于等于cpu的核数
    # 第一个参数是一个函数体，不需要加括号，也不需指定参数。。
    #  第二个参数是一个列表，列表中的每个参数都会传给那个函数体
    pool.map(to_mongo_pool,[i for i in range(PAGE_SUM)])
    # close它只是把进程池关闭
    pool.close()
    # join起到一个阻塞的作用，主进程要等待子进程运行完，才能接着往下运行
    pool.join()
    end_time = time.time()
    print("总耗费时间%.2f秒" % (end_time - start_time))