解析一個本地網頁，獲取標題，圖片地址，價格，評分量和評分星級。
網頁如下

作業1.2.png

代碼

from bs4 import BeautifulSoup
with open('D:\宣宣\homework/index.html','r') as wb_data:
    soup = BeautifulSoup(wb_data,'lxml') #解析網頁內容
    images = soup.select('body > div > div > div.col-md-9 > div > div > div > img')
    tittles = soup.select('body > div > div > div.col-md-9 > div > div > div > div.caption > h4 > a')
    prices = soup.select('body > div > div > div.col-md-9 > div > div > div > div.caption > h4.pull-right')
    reviews = soup.select('body > div > div > div.col-md-9 > div > div > div > div.ratings > p.pull-right')
    stars = soup.select('body > div > div > div.col-md-9 > div > div > div > div.ratings > p:nth-of-type(2)')



   # print(images,tittles,price,reviews,stars,sep= '\n--------------\n')

    for tittle,image,price,review,star in zip(tittles,images,prices,reviews,stars):
        data = {
            'tittle':tittle.get_text(), #提取文本信息
            'image':image.get('src'), #提取圖片地址src是地址參數
            'price':price.get_text(),
            'review':review.get_text(),
            'star':len(star.find_all("span",class_='glyphicon glyphicon-star'))
        }
        print(data)
'''
body > div:nth-child(2) > div > div.col-md-9 > div:nth-child(2) > div:nth-child(1) > div > img
body > div:nth-child(2) > div > div.col-md-9 > div:nth-child(2) > div:nth-child(1) > div > div.caption > h4:nth-child(2) > a
body > div:nth-child(2) > div > div.col-md-9 > div:nth-child(2) > div:nth-child(1) > div > div.ratings > p:nth-child(2) > span:nth-child(3)
body > div:nth-child(2) > div > div.col-md-9 > div:nth-child(2) > div:nth-child(1) > div > div.ratings > p.pull-right
body > div:nth-child(2) > div > div.col-md-9 > div:nth-child(2) > div:nth-child(1) > div > div.caption > h4.pull-right

運行結果

122.png

總結

1.用Python爬取網頁信息，首先得對網頁有基本的了解。知道如何在瀏覽器查詢對應圖片、文字的HTML代碼。再通過copy CSS selector進行有用信息的提取
2.在星級提取中，stars = soup.select('body > div > div > div.col-md-9 > div > div > div > div.ratings > p:nth-of-type(2)')，copy CSS selector是body > div:nth-child(2) > div > div.col-md-9 > div:nth-child(2) > div:nth-child(1) > div > div.ratings > p:nth-child(2) > span:nth-child(3)，開始沒把最后的span:nth-child(3)這一串去掉，結果star=0.后來才明白要提取總共多少個星星，應該寫到父級標簽 p:nth-child(2) ，才會統計所有。nth-child是會出錯的。應改為nth-of-type(2)，意為選擇器匹配屬于父元素的特定類型的第 2個子元素的每個元素。
3.通過不停的出錯，對照答案，查文檔，對代碼的理解加深的。最后運行代碼成功，又是一件喜悅的事情，學習動力持續不斷。