Python下selenium的實戰和普通爬蟲的對比

1.普通爬取數據

"""普通爬取數據爬蟲，只要有反爬，cookie就不是很穩定。並不利於數據爬取"""
import requests
import re
from lxml import etree


headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3554.0 Safari/537.36",
        "Referer": "https://www.lagou.com/jobs/list_python?labelWords=&fromSearch=true&suginput=",
        # Cookie需要時常換取
        "Cookie": "_ga=GA1.2.1553999204.1538311958; user_trace_token=20180930205504-0cebb367-c4b0-11e8-bb68-5254005c3644; "
                  "LGUID=20180930205504-0cebbcd1-c4b0-11e8-bb68-5254005c3644; showExpriedIndex=1; showExpriedCompanyHome=1; "
                  "showExpriedMyPublish=1; index_location_city=%E6%B7%B1%E5%9C%B3; sensorsdata2015jssdkcross=%7B%22distinct_"
                  "id%22%3A%22166811f974d15e-026ab47692a8d1-181c7151-2073600-166811f974e549%22%2C%22%24device_id%22%3A%2216681"
                  "1f974d15e-026ab47692a8d1-181c7151-2073600-166811f974e549%22%7D; LG_LOGIN_USER_ID=1d0d39f3227c1f914a3f9c4d95f"
                  "4816a5c6667141cc1313edac4603b4bd6d789; hasDeliver=6; _gid=GA1.2.2026255269.1540465512; WEBTJ-ID=2018102519420"
                  "2-166ab0808f9cb-06806b898438ec-181c7151-2073600-166ab0808fb7ef; Hm_lvt_4233e74dff0ae5bd0a3d81c6ccf756e6=15401"
                  "21809,1540210602,1540465512,1540467723; LGSID=20181025194505-6ab63d2a-d84b-11e8-8168-5254005c3644; PRE_UTM=m_cf_"
                  "cpt_baidu_pc; PRE_HOST=www.baidu.com; PRE_SITE=https%3A%2F%2Fwww.baidu.com%2Fs%3Fie%3Dutf-8%26f%3D8%26rsv_bp%3D0%2"
                  "6rsv_idx%3D1%26tn%3Dbaidu%26wd%3D%25E6%258B%2589%25E5%258B%25BE%25E7%25BD%2591%26rsv_pq%3D8d0dc05a0000aada%26rsv_t%"
                  "3D4664T41fswButqvfw6ZM6FGWfkWjtwR%252Fmpsskb6hctTVnUHewMo9o1%252BqRGk%26rqlang%3Dcn%26rsv_enter%3D1%26rsv_sug3%3D7%26r"
                  "sv_sug1%3D8%26rsv_sug7%3D100; PRE_LAND=https%3A%2F%2Fwww.lagou.com%2Flp%2Fhtml%2Fcommon.html%3Futm_source%3Dm_cf_cpt_baidu_pc;"
                  " _putrc=1D33894D7A6BEB76123F89F2B170EADC; JSESSIONID=ABAAABAAAGFABEF9CEC8B1F38F5075A286961D31667AC5C; login=true; unick=%E6%9D%A"
                  "8%E7%A6%B9; gate_login_token=b0629019d50bbe97eb829d61be9770ad4b570c1e68e239c68ae16cc71c68c808; _gat=1; Hm_lpvt_4233e74dff0ae5bd0a"
                  "3d81c6ccf756e6=1540469398; LGRID=20181025201301-5183464a-d84f-11e8-a347-525400f775ce; TG-TRACK-CODE=index_search; SEARCH_ID=06714"
                  "3e245964eb7af08d8c8d316cd44"
    }


def request_list_page():
    # 獲取詳情頁面url
    url = "https://www.lagou.com/jobs/positionAjax.json?city=%E6%B7%B1%E5%9C%B3&needAddtionalResult=false"
    data = {
        "first": "false",
        "pn": 1,
        "kd": "Python"
    }
    for x in range(1, 31):
        data["pn"] = x
        rep = requests.post(url=url, headers=headers, data=data)
        # json方法，如果返回來的是json數據，自動轉換為字典
        result = rep.json()
        # json在線解析分析數據格式
        positions = result["content"]["positionResult"]["result"]
        for position in positions:
            positionId = position["positionId"]
            # 找到詳情頁url，並傳遞給解析函數
            position_url = "https://www.lagou.com/jobs/{}.html".format(positionId)
            parse_position_detail(position_url)
            break
        break


def parse_position_detail(url):
    # 頁面解析
    res = requests.get(url, headers=headers)
    text = res.text
    html = etree.HTML(text)
    position_depart = html.xpath("//div[@class='company']/text()")
    position_names = html.xpath("//span[@class='name']/text()")
    job_requests = html.xpath("//dd[@class='job_request']//span/text()")
    salary_span = re.sub(r"[\s/]", "", job_requests[0].strip())
    addr_span = re.sub(r"[\s/]", "", job_requests[1].strip())
    exper_span = re.sub(r"[\s/]", "", job_requests[2].strip())
    education_span = re.sub(r"[\s/]", "", job_requests[3].strip())
    full_span = re.sub(r"[\s/]", "", job_requests[4].strip())
    desc = "".join(html.xpath("//dd[@class='job_bt']//text()")).strip()
    print(position_depart, position_names, salary_span, addr_span, exper_span, education_span, full_span, desc)


if __name__ == '__main__':
    request_list_page()

2.操作selenium獲取數據

"""selenium自動化爬取，模擬人的動作，操作瀏覽器訪問"""
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from lxml import etree
import random
import csv
import time
import re


class LagouSpider(object):
    # 獲取chromedriver.exe路徑
    driver_path = r"E:\Program Files\chromedriver.exe"

    def __init__(self):
        # 實例化這個路徑
        self.driver = webdriver.Chrome(executable_path=LagouSpider.driver_path)
        self.url = "https://www.lagou.com/jobs/list_python?city=全國&cl=false&fromSearch=true&labelWords=&suginput="

    def run(self):
        # 頁面列表僅限一次，取出while循環
        self.driver.get(self.url)
        while True:
            # 獲取頁面源碼
            source = self.driver.page_source
            # 有異步加載，數據出來的慢，需要等待
            WebDriverWait(driver=self.driver, timeout=10).until(
                EC.presence_of_element_located((By.XPATH, "//div[@class='pager_container']/span[last()]"))
            )
            # 將完整的源碼傳遞給函數解析
            self.parse_list_page(source)
            try:
                # 獲取下一頁點擊標簽
                next_btn = self.driver.find_element_by_xpath("//div[@class='pager_container']/span[last()]")
                # 是最后一頁，停止循環
                if "pager_next_disabled" in next_btn.get_attribute("class"):
                    break
                else:
                    # 繼續循環
                    next_btn.click()
            except:
                print(source)
            time.sleep(1)

    def parse_list_page(self, source):
        # 獲取詳情url
        html = etree.HTML(source)
        links = html.xpath("//a[@class='position_link']/@href")
        for link in links:
            # 將獲取的url傳遞給函數
            self.request_detail_page(link)
            time.sleep(random.randint(0, 2))

    def request_detail_page(self, url):
        # 打開新的頁面窗口
        self.driver.execute_script("window.open('%s')" % url)
        # 移動到新的頁面窗口
        self.driver.switch_to.window(self.driver.window_handles[1])
        # 有異步加載，數據出來的慢，需要等待
        WebDriverWait(self.driver, timeout=10).until(
            EC.presence_of_element_located((By.XPATH, "//div[@class='job-name']/span[@class='name']"))
        )
        source = self.driver.page_source
        # 將源碼傳遞給函數解析
        self.parse_detail_page(source)
        # 關閉當前這個詳情頁
        self.driver.close()
        # 繼續切換回職位列表頁
        self.driver.switch_to.window(self.driver.window_handles[0])

    def parse_detail_page(self, source):
        # 開始解析數據(不做介紹,前面有詳解)
        html = etree.HTML(source)
        position_name = html.xpath("//span[@class='name']/text()")[0]
        job_request_spans = html.xpath("//dd[@class='job_request']//span")
        salary = job_request_spans[0].xpath(".//text()")[0].strip()
        city = job_request_spans[1].xpath(".//text()")[0].strip()
        city = re.sub(r'[\s/]]', "", city)
        work_years = job_request_spans[2].xpath(".//text()")[0].strip()
        work_years = re.sub(r'[\s/]]', "", work_years)
        education = job_request_spans[3].xpath(".//text()")[0].strip()
        education = re.sub(r'[\s/]]', "", education)
        desc = "".join(html.xpath("//dd[@class='job_bt']//text()")).strip()
        company_name = html.xpath("//h2[@class='fl']/text()")[0].strip()
        position = {(position_name, company_name, salary, city, work_years, education, desc)}
        with open("lagou.csv", "a+", encoding="utf-8", newline="") as fp:
            writer = csv.writer(fp)
            writer.writerows(position)


if __name__ == '__main__':
    spider = LagouSpider()
    spider.run()

3.操作selenium爬取boss直聘

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from lxml import etree
import random
import time
import csv
import re


class BossSpider(object):
    # 獲取chromedriver.exe路徑
    driver_path = r"E:\Program Files\chromedriver.exe"

    def __init__(self):
        # 實例化對象
        self.driver = webdriver.Chrome(executable_path=BossSpider.driver_path)
        self.url = "https://www.zhipin.com/job_detail/?query=python&scity=100010000&industry=&position="

    def run(self):
        # 獲取頁面列表
        self.driver.get(self.url)
        while True:
            # 獲取頁面列表源碼
            source = self.driver.page_source
            # 有異步加載，數據出來的慢，需要等待
            WebDriverWait(driver=self.driver, timeout=10).until(
                EC.presence_of_element_located((By.XPATH, "//div[@class='page']/a[last()]"))
            )
            # 將完整的源碼傳遞給函數解析
            self.parse_list_page(source)
            try:
                # 獲取下一頁點擊標簽
                next_btn = self.driver.find_element_by_xpath("//div[@class='page']/a[last()]")
                # 是最后一頁，停止循環
                if "next disabled" in next_btn.get_attribute("class"):
                    break
                else:
                    # 繼續循環
                    next_btn.click()
            except:
                print(source)
            time.sleep(random.randint(1, 5))

    def parse_list_page(self, source):
        html = etree.HTML(source)
        # 獲取詳情url
        links = html.xpath("//div[@class='info-primary']//a/@href")
        for link in links:
            url = "https://www.zhipin.com" + link
            # 將獲取的url傳遞給函數
            self.request_detail_page(url)
            time.sleep(random.randint(1, 5))

    def request_detail_page(self, url):
        # 打開新的頁面窗口
        self.driver.execute_script("window.open('%s')" % url)
        # 移動到新的頁面窗口
        self.driver.switch_to.window(self.driver.window_handles[1])
        # 有異步加載，數據出來的慢，需要等待
        WebDriverWait(self.driver, timeout=10).until(
            EC.presence_of_element_located((By.XPATH, "//div[@class='info-primary']//div[@class='name']"))
        )
        source = self.driver.page_source
        # 將完整的源碼傳遞給函數解析
        self.parse_detail_page(source)
        # 關閉當前這個詳情頁
        self.driver.close()
        # 繼續切換回列表頁
        self.driver.switch_to.window(self.driver.window_handles[0])

    def parse_detail_page(self, source):
        # 開始解析並獲取數據
        html = etree.HTML(source)
        position_name = html.xpath("//div[@class='name']/h1/text()")[0].strip()
        company_name = html.xpath("//div[@class='info-company']//h3[@class='name']/a/text()")[0].strip()
        salary = html.xpath("//div[@class='name']/span[@class='badge']/text()")[0].strip()
        job_request_ps = html.xpath("//div[@class='info-primary']//p/text()")
        city = job_request_ps[0].strip()
        work_years = job_request_ps[1].strip()
        education = job_request_ps[2].strip()
        desc_tags = html.xpath("//div[@class='job-sec']/div[@class='text']")
        contents = ""
        for desc in desc_tags:
            tag_list = desc.xpath("./text()")
            for tag in tag_list:
                # 替換無用字符串
                text = re.sub(r"[\s\\\xa0]", "", tag)
                contents += text
        position = {(position_name, company_name, salary, city, work_years, education, contents)}
        # 打開文件以utf-8編碼不換行進行追加，
        with open("boss.csv", "a+", encoding="utf-8", newline="") as fp:
            writer = csv.writer(fp)
            writer.writerows(position)


if __name__ == '__main__':
    spider = BossSpider()
    spider.run()

4.12306搶票初步實現地址，內有包含步驟和說明

https://github.com/yangyu57587720/12306GrabVotes