[爬虫]关于XPath表达式

DrWhiter

我试着运行下方的代码：

1. import requests
   
2. from selenium import webdriver
   
3. from lxml import etree
   
4. import time
   
5. from bs4 import BeautifulSoup     # 导入所需模块
   
6. last = []
   
7. # list_url = ['http://nce.koolearn.com/20150122/781915.html', 'http://nce.koolearn.com/20150122/781916.html', 'http://nce.koolearn.com/20150122/781917.html', 'http://nce.koolearn.com/20150122/781918.html', 'http://nce.koolearn.com/20150122/781919.html', 'http://nce.koolearn.com/20150122/781920.html', 'http://nce.koolearn.com/20150122/781921.html', 'http://nce.koolearn.com/20150122/781922.html', 'http://nce.koolearn.com/20150122/781923.html', 'http://nce.koolearn.com/20150122/781924.html', 'http://nce.koolearn.com/20150123/781955.html', 'http://nce.koolearn.com/20150123/781956.html', 'http://nce.koolearn.com/20150123/781957.html', 'http://nce.koolearn.com/20150123/781958.html', 'http://nce.koolearn.com/20150123/781959.html', 'http://nce.koolearn.com/20150123/781960.html', 'http://nce.koolearn.com/20150123/781961.html', 'http://nce.koolearn.com/20150123/781962.html', 'http://nce.koolearn.com/20150123/781963.html', 'http://nce.koolearn.com/20150123/781964.html', 'http://nce.koolearn.com/20150126/781995.html', 'http://nce.koolearn.com/20150126/781996.html', 'http://nce.koolearn.com/20150126/781997.html', 'http://nce.koolearn.com/20150126/781998.html', 'http://nce.koolearn.com/20150126/781999.html', 'http://nce.koolearn.com/20150127/782015.html', 'http://nce.koolearn.com/20150127/782016.html', 'http://nce.koolearn.com/20150127/782017.html', 'http://nce.koolearn.com/20150127/782018.html', 'http://nce.koolearn.com/20150127/782019.html', 'http://nce.koolearn.com/20150128/782040.html', 'http://nce.koolearn.com/20150128/782041.html', 'http://nce.koolearn.com/20150128/782042.html', 'http://nce.koolearn.com/20150128/782043.html', 'http://nce.koolearn.com/20150128/782044.html', 'http://nce.koolearn.com/20150129/782060.html', 'http://nce.koolearn.com/20150129/782061.html', 'http://nce.koolearn.com/20150129/782062.html', 'http://nce.koolearn.com/20150129/782063.html', 'http://nce.koolearn.com/20150129/782064.html', 'http://nce.koolearn.com/20150130/782080.html', 'http://nce.koolearn.com/20150130/782081.html', 'http://nce.koolearn.com/20150130/782082.html', 'http://nce.koolearn.com/20150130/782083.html', 'http://nce.koolearn.com/20150130/782084.html', 'http://nce.koolearn.com/20150202/782103.html', 'http://nce.koolearn.com/20150202/782104.html', 'http://nce.koolearn.com/20150202/782105.html', 'http://nce.koolearn.com/20150202/782106.html', 'http://nce.koolearn.com/20150202/782107.html', 'http://nce.koolearn.com/20150203/782113.html', 'http://nce.koolearn.com/20150203/782114.html', 'http://nce.koolearn.com/20150203/782115.html', 'http://nce.koolearn.com/20150203/782116.html', 'http://nce.koolearn.com/20150203/782117.html', 'http://nce.koolearn.com/20150204/782129.html', 'http://nce.koolearn.com/20150204/782130.html', 'http://nce.koolearn.com/20150204/782131.html', 'http://nce.koolearn.com/20150204/782132.html', 'http://nce.koolearn.com/20150204/782133.html', 'http://nce.koolearn.com/20150205/782144.html', 'http://nce.koolearn.com/20150205/782145.html', 'http://nce.koolearn.com/20150205/782146.html', 'http://nce.koolearn.com/20150205/782147.html', 'http://nce.koolearn.com/20150205/782148.html', 'http://nce.koolearn.com/20150206/782154.html', 'http://nce.koolearn.com/20150206/782155.html', 'http://nce.koolearn.com/20150206/782156.html', 'http://nce.koolearn.com/20150206/782157.html', 'http://nce.koolearn.com/20150206/782158.html', 'http://nce.koolearn.com/20150206/782159.html', 'http://nce.koolearn.com/20150206/782160.html']
   
8. def get_text(url):
   
9.     headers = {"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36"}   # 标头
   
10.     reponse = requests.get(url=url,headers=headers)    # 获得字节码
    
11.     reponse.encoding = "utf-8"     # 指定编码方式避免乱码
    
12.     global result
    
13.     result = reponse.text   # 获取网页源代码
    
14.     """
    
15.     soup = BeautifulSoup(result,"lxml")
    
16.     global b
    
17.     b = soup.select('.xqy_container.w1200>.xqy_container_box>.xqy_core>.xqy_core_main>.xqy_core_text>p')
    
18.     for test in range(len(b)):
    
19.         b[test] = str(b[test])
    
20.         b[test] = b[test].replace("<p>","")
    
21.         b[test] = b[test].replace("</p>","")
    
22.         b[test] = b[test].replace("\u3000","")
    
23.     """
    
24.     # 以上为不需执行的部分，可以直接略过
    
25.     global c
    
26.     global d
    
27.     c = etree.HTML(result)   # 实例化etree对象
    
28.     d = c.xpath("/html/body/div[4]/div[2]/div[1]/div[1]/div[3]/p[2]//text()")    # 通过XPath获取信息
    
29. 
    
30. i = 'http://nce.koolearn.com/20150122/781915.html'  # 指定url
    
31. get_text(i)
    

复制代码

.
当我试着获取d的值时，却返回了一个空列表，我该怎么办？
PS：我可以用代码中的XPath表达式在网页中找到相应元素

Twilight6

改成这样试试看：

1. d = c.xpath('//div[@class="xqy_core_main"]/div/p/text()')

复制代码

wp231957

想抓哪部分数据