etree和Beautiful Soup的使用

1.lxml 是一種使用 Python 編寫的庫,可以迅速、靈活地處理 XML ，支持 XPath (XML Path Language)，使用 lxml 的 etree 庫來進行爬取網站信息

2.Beautiful Soup支持從HTML或XML文件中提取數據的Python庫；支持Python標准庫中的HTML解析器；還支持一些第三方的解析器lxml, 使用的是 Xpath 語法

Beautiful Soup自動將輸入文檔轉換為Unicode編碼，輸出文檔轉換為utf-8編碼。

我們爬取騰訊招聘網站的鏈接為https://hr.tencent.com/position.php?&start=10#a

需要獲取職位名稱、職位類別、招聘人數、工作地點、發布時間等信息

一、使用etree爬取信息

1.導入庫

from lxml import etree
from urllib import request#進一步了解urllib和requests的區別
import json

 

在python.3中使用urllib庫中的request模塊,保存輸出為json文件

2.獲取網站並寫到json文件中

response=request.urlopen('https://hr.tencent.com/position.php?&start=10#a')#獲取網站鏈接
resHtml=response.read()
output=open('tencent1.json','wb+')#使用二進制方式打開，寫入到json文件

 

如果只使用w來寫入文件會報錯：

 write() argument must be str, not bytes 

我們需要用二進制來打開改為wb+

3.獲取我們需要得到的標簽

 

html=etree.HTML(resHtml)
result=html.xpath('//tr[@class="odd"] | //tr[@class="even"]')#獲取tr標簽下的所有class只有odd和even,用|並列
for site in result:
    item={ }

 

必須是字典形式，先定義一個空字典

    name=site.xpath('./td[1]/a')[0].text
    detailLink=site.xpath('./td[1]/a')[0].attrib['href']
    catalog=site.xpath('./td[2]')[0].text
    recruitNumber=site.xpath('./td[3]')[0].text
    workLocation=site.xpath('./td[4]')[0].text
    publishTime=site.xpath('./td[5]')[0].text

 

找到我們需要的字段

4.規范輸出形式

    print(type(name))
    print(name,detailLink,catalog,recruitNumber,workLocation,publishTime)
    item['name']=name
    item['detailLink']=detailLink
    item['catalog']=catalog
    item['recruitNumber']=recruitNumber
    item['publishTime']=publishTime

    line = json.dumps(item,ensure_ascii=False) + '\n'
    print(line)
    output.write(line.encode('utf-8'))#編碼格式

output.close()

 

運行后結果如下：

<class 'str'>
23677-互娛服務采購經理 position_detail.php?id=44802&keywords=&tid=0&lid=0 職能類 1 深圳 2018-10-16
{"catalog": "職能類", "name": "23677-互娛服務采購經理", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44802&keywords=&tid=0&lid=0"}

<class 'str'>
22989-騰訊雲塊存儲底層開發工程師（深圳） position_detail.php?id=44803&keywords=&tid=0&lid=0 技術類 2 深圳 2018-10-16
{"catalog": "技術類", "name": "22989-騰訊雲塊存儲底層開發工程師（深圳）", "recruitNumber": "2", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44803&keywords=&tid=0&lid=0"}

<class 'str'>
24549-渠道管理經理（政策管理方向-上海） position_detail.php?id=44804&keywords=&tid=0&lid=0 市場類 1 上海 2018-10-16
{"catalog": "市場類", "name": "24549-渠道管理經理（政策管理方向-上海）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44804&keywords=&tid=0&lid=0"}

<class 'str'>
24549-渠道管理經理（ROC管理方向-上海） position_detail.php?id=44805&keywords=&tid=0&lid=0 市場類 1 上海 2018-10-16
{"catalog": "市場類", "name": "24549-渠道管理經理（ROC管理方向-上海）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44805&keywords=&tid=0&lid=0"}

<class 'str'>
24549-廣告營銷業務分析師（上海） position_detail.php?id=44806&keywords=&tid=0&lid=0 市場類 1 上海 2018-10-16
{"catalog": "市場類", "name": "24549-廣告營銷業務分析師（上海）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44806&keywords=&tid=0&lid=0"}

<class 'str'>
28297-RPG手游—市場和平台渠道推廣（深圳） position_detail.php?id=44809&keywords=&tid=0&lid=0 產品/項目類 1 深圳 2018-10-16
{"catalog": "產品/項目類", "name": "28297-RPG手游—市場和平台渠道推廣（深圳）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44809&keywords=&tid=0&lid=0"}

<class 'str'>
21309-在線教育-運營視覺設計師（深圳） position_detail.php?id=44800&keywords=&tid=0&lid=0 設計類 2 深圳 2018-10-16
{"catalog": "設計類", "name": "21309-在線教育-運營視覺設計師（深圳）", "recruitNumber": "2", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44800&keywords=&tid=0&lid=0"}

<class 'str'>
21309-在線教育-UI設計師（深圳） position_detail.php?id=44801&keywords=&tid=0&lid=0 設計類 2 深圳 2018-10-16
{"catalog": "設計類", "name": "21309-在線教育-UI設計師（深圳）", "recruitNumber": "2", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44801&keywords=&tid=0&lid=0"}

<class 'str'>
22989-數據庫高級產品運營經理 position_detail.php?id=44795&keywords=&tid=0&lid=0 產品/項目類 1 北京 2018-10-16
{"catalog": "產品/項目類", "name": "22989-數據庫高級產品運營經理", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44795&keywords=&tid=0&lid=0"}

<class 'str'>
27087-海外區域中心空間運營經理（深圳） position_detail.php?id=44797&keywords=&tid=0&lid=0 市場類 1 深圳 2018-10-16
{"catalog": "市場類", "name": "27087-海外區域中心空間運營經理（深圳）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44797&keywords=&tid=0&lid=0"}

 

導出的json文件如下：

{"catalog": "職能類", "name": "23677-互娛服務采購經理", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44802&keywords=&tid=0&lid=0"}
{"catalog": "技術類", "name": "22989-騰訊雲塊存儲底層開發工程師（深圳）", "recruitNumber": "2", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44803&keywords=&tid=0&lid=0"}
{"catalog": "市場類", "name": "24549-渠道管理經理（政策管理方向-上海）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44804&keywords=&tid=0&lid=0"}
{"catalog": "市場類", "name": "24549-渠道管理經理（ROC管理方向-上海）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44805&keywords=&tid=0&lid=0"}
{"catalog": "市場類", "name": "24549-廣告營銷業務分析師（上海）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44806&keywords=&tid=0&lid=0"}
{"catalog": "產品/項目類", "name": "28297-RPG手游—市場和平台渠道推廣（深圳）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44809&keywords=&tid=0&lid=0"}
{"catalog": "設計類", "name": "21309-在線教育-運營視覺設計師（深圳）", "recruitNumber": "2", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44800&keywords=&tid=0&lid=0"}
{"catalog": "設計類", "name": "21309-在線教育-UI設計師（深圳）", "recruitNumber": "2", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44801&keywords=&tid=0&lid=0"}
{"catalog": "產品/項目類", "name": "22989-數據庫高級產品運營經理", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44795&keywords=&tid=0&lid=0"}
{"catalog": "市場類", "name": "27087-海外區域中心空間運營經理（深圳）", "recruitNumber": "1", "publishTime": "2018-10-16", "detailLink": "position_detail.php?id=44797&keywords=&tid=0&lid=0"}

 

 

二、使用Beautiful Soup爬取信息

1.導入庫

 from bs4 import BeautifulSoup 2 from urllib import request 3 import json 

2.獲取網站並寫到json文件中

 

response=request.urlopen('https://hr.tencent.com/position.php?&start=10#a')
resHtml=response.read()
output=open('tencent2.json','wb+')

 

3.獲取我們需要得到的標簽

html = BeautifulSoup(resHtml,'lxml')
result = html.select('tr[class="even"]')
result2= html.select('tr[class="odd"]')
result+=result2
print(len(result))

for site in result:
    item = {}

    name = site.select('td a')[0].get_text()
    detailLink = site.select('td a')[0].attrs['href']#Tag就是 HTML 中的一個個標簽，它的兩個屬性是name和attrs
    catalog = site.select('td ')[1].get_text()
    recruitNumber = site.select('td ')[2].get_text()
    workLocation = site.select('td ')[3].get_text()
    publishTime = site.select('td ')[4].get_text()

 

4.規范輸出形式

 item['name']=name
    item['detailLink'] = detailLink
    item['catalog'] = catalog
    item['recruitNumber'] = recruitNumber
    item['workLocation'] = workLocation
    item['publishTime'] = publishTime

    line = json.dumps(item,ensure_ascii=False)
    print(line)

    output.write(line.encode('utf-8'))

output.close()

 

運行結果如下：

10
{"detailLink": "position_detail.php?id=44802&keywords=&tid=0&lid=0", "catalog": "職能類", "publishTime": "2018-10-16", "recruitNumber": "1", "name": "23677-互娛服務采購經理", "workLocation": "深圳"}
{"detailLink": "position_detail.php?id=44804&keywords=&tid=0&lid=0", "catalog": "市場類", "publishTime": "2018-10-16", "recruitNumber": "1", "name": "24549-渠道管理經理（政策管理方向-上海）", "workLocation": "上海"}
{"detailLink": "position_detail.php?id=44806&keywords=&tid=0&lid=0", "catalog": "市場類", "publishTime": "2018-10-16", "recruitNumber": "1", "name": "24549-廣告營銷業務分析師（上海）", "workLocation": "上海"}
{"detailLink": "position_detail.php?id=44800&keywords=&tid=0&lid=0", "catalog": "設計類", "publishTime": "2018-10-16", "recruitNumber": "2", "name": "21309-在線教育-運營視覺設計師（深圳）", "workLocation": "深圳"}
{"detailLink": "position_detail.php?id=44795&keywords=&tid=0&lid=0", "catalog": "產品/項目類", "publishTime": "2018-10-16", "recruitNumber": "1", "name": "22989-數據庫高級產品運營經理", "workLocation": "北京"}
{"detailLink": "position_detail.php?id=44803&keywords=&tid=0&lid=0", "catalog": "技術類", "publishTime": "2018-10-16", "recruitNumber": "2", "name": "22989-騰訊雲塊存儲底層開發工程師（深圳）", "workLocation": "深圳"}
{"detailLink": "position_detail.php?id=44805&keywords=&tid=0&lid=0", "catalog": "市場類", "publishTime": "2018-10-16", "recruitNumber": "1", "name": "24549-渠道管理經理（ROC管理方向-上海）", "workLocation": "上海"}
{"detailLink": "position_detail.php?id=44809&keywords=&tid=0&lid=0", "catalog": "產品/項目類", "publishTime": "2018-10-16", "recruitNumber": "1", "name": "28297-RPG手游—市場和平台渠道推廣（深圳）", "workLocation": "深圳"}
{"detailLink": "position_detail.php?id=44801&keywords=&tid=0&lid=0", "catalog": "設計類", "publishTime": "2018-10-16", "recruitNumber": "2", "name": "21309-在線教育-UI設計師（深圳）", "workLocation": "深圳"}
{"detailLink": "position_detail.php?id=44797&keywords=&tid=0&lid=0", "catalog": "市場類", "publishTime": "2018-10-16", "recruitNumber": "1", "name": "27087-海外區域中心空間運營經理（深圳）", "workLocation": "深圳"}

 

以上為兩種方法爬取網站信息，個人覺得用Beautiful Soup爬取比較方便