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()