三種資料抓取的方法
- 正則運算式（re庫）
- BeautifulSoup（bs4）
- lxml
*利用之前構建的下載網頁函式，獲取目標網頁的html，我們以https://guojiadiqu.bmcx.com/AFG__guojiayudiqu/為例，獲取html，
from get_html import download
url = 'https://guojiadiqu.bmcx.com/AFG__guojiayudiqu/'
page_content = download(url)
*假設我們需要爬取該網頁中的國家名稱和概況，我們依次使用這三種資料抓取的方法實作資料抓取，
1.正則運算式
from get_html import download
import re
url = 'https://guojiadiqu.bmcx.com/AFG__guojiayudiqu/'
page_content = download(url)
country = re.findall('class="h2dabiaoti">(.*?)</h2>', page_content) #注意回傳的是list
survey_data = re.findall('<tr><td bgcolor="#FFFFFF" id="wzneirong">(.*?)</td></tr>', page_content)
survey_info_list = re.findall('<p> (.*?)</p>', survey_data[0])
survey_info = ''.join(survey_info_list)
print(country[0],survey_info)
2.BeautifulSoup（bs4）
from get_html import download
from bs4 import BeautifulSoup
url = 'https://guojiadiqu.bmcx.com/AFG__guojiayudiqu/'
html = download(url)
#創建 beautifulsoup 物件
soup = BeautifulSoup(html,"html.parser")
#搜索
country = soup.find(attrs={'class':'h2dabiaoti'}).text
survey_info = soup.find(attrs={'id':'wzneirong'}).text
print(country,survey_info)
3.lxml
from get_html import download
from lxml import etree #決議樹
url = 'https://guojiadiqu.bmcx.com/AFG__guojiayudiqu/'
page_content = download(url)
selector = etree.HTML(page_content)#可進行xpath決議
country_select = selector.xpath('//*[@id="main_content"]/h2') #回傳串列
for country in country_select:
print(country.text)
survey_select = selector.xpath('//*[@id="wzneirong"]/p')
for survey_content in survey_select:
print(survey_content.text,end='')
運行結果：
最后，參考《用python寫網路爬蟲》中對三種方法的性能對比，如下圖：
僅供參考，
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標籤：python
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