多线程爬虫:即程序中的某些程序段并行执行,
合理地设置多线程,可以让爬虫效率更高
糗事百科段子普通爬虫和多线程爬虫
分析该网址链接得出:
https://www.qiushibaike.com/8hr/page/页码/
多线程爬虫也就和JAVA的多线程差不多,直接上代码
1 '''
2 #此处代码为普通爬虫
3 import urllib.request
4 import urllib.error
5 import re
6
7 headers = ("User-Agent","Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36")
8 opener = urllib.request.build_opener()
9 opener.addheaders = [headers]
10 urllib.request.install_opener(opener)
11 for i in range(1,2):
12 url = "https://www.qiushibaike.com/8hr/page/"+str(i)+"/"
13 pagedata = urllib.request.urlopen(url).read().decode("utf-8","ignore")
14 pattern = '<div class="content">.*?<span>(.*?)</span>(.*?)</div>'
15 datalist = re.compile(pattern,re.S).findall(pagedata)
16 for j in range(0,len(datalist)):
17 print("第"+str(i)+"页第"+str(j)+"个段子内容是:")
18 print(datalist[j])
19 '''
20
21 '''
22 #此处为多线程介绍代码
23 import threading #导入多线程包
24 class A(threading.Thread): #创建一个多线程A
25 def __init__(self): #必须包含的两个方法之一:初始化线程
26 threading.Thread.__init__(self)
27 def run(self): #必须包含的两个方法之一:线程运行方法
28 for i in range(0,11):
29 print("我是线程A")
30
31 class B(threading.Thread): #创建一个多线程A
32 def __init__(self): #必须包含的两个方法之一:初始化线程
33 threading.Thread.__init__(self)
34 def run(self): #必须包含的两个方法之一:线程运行方法
35 for i in range(0,11):
36 print("我是线程B")
37
38 t1 = A() #线程实例化
39 t1.start() #线程运行
40 t2 = B()
41 t2.start()
42 '''
43
44
45 #此处为修改后的多线程爬虫
46 #使用多线程进行奇偶页的爬取
47 import urllib.request
48 import urllib.error
49 import re
50 import threading
51
52 headers = ("User-Agent","Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36")
53 opener = urllib.request.build_opener()
54 opener.addheaders = [headers]
55 urllib.request.install_opener(opener)
56 class one(threading.Thread): #爬取奇数页内容
57 def __init__(self):
58 threading.Thread.__init__(self)
59 def run(self):
60 for i in range(1,12,2):
61 url = "https://www.qiushibaike.com/8hr/page/"+str(i)+"/"
62 pagedata = urllib.request.urlopen(url).read().decode("utf-8","ignore")
63 pattern = '<div class="content">.*?<span>(.*?)</span>(.*?)</div>'
64 datalist = re.compile(pattern,re.S).findall(pagedata)
65 for j in range(0,len(datalist)):
66 print("第"+str(i)+"页第"+str(j)+"段子内容为:")
67 print(datalist[j])
68
69
70 class two(threading.Thread): #爬取奇数页内容
71 def __init__(self):
72 threading.Thread.__init__(self)
73 def run(self):
74 for i in range(2,12,2):
75 url = "https://www.qiushibaike.com/8hr/page/"+str(i)+"/"
76 pagedata = urllib.request.urlopen(url).read().decode("utf-8","ignore")
77 pattern = '<div class="content">.*?<span>(.*?)</span>(.*?)</div>'
78 datalist = re.compile(pattern,re.S).findall(pagedata)
79 for j in range(0,len(datalist)):
80 print("第"+str(i)+"页第"+str(j)+"段子内容为:")
81 print(datalist[j])
82 t1 = one()
83 t2 = two()
84 t1.start()
85 t2.start()