python3爬取百度贴吧

import urllib
import urllib.request

def loadPage(url,filename):
    """
        作用：根据url发送请求=，获取服务器响应文件
        url：需要爬去的url
        filename:处理得文件名
    """
    print("正在下载" + filename)
    headers = {"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36"}
    req = urllib.request.Request(url, headers = headers)
    return urllib.request.urlopen(req).read()

def writePage(html,filename):
    """
        作用:将HTML内容写入到本地
        html:服务器响应得文件内容
        
    """
    print("正在保存" + filename)
    #文件写入
    with open(filename,"wb") as f:
        f.write(html)
    print ("_" * 30)


def tiebaSpider(fullurl,beginPage,endPage):
    """
        作用：贴吧爬虫调度器，负责处理每个页面得url
        url：贴吧url的前部分
        beginPage：起始页
        endPage：结束页
    """
    for page in range(beginPage,endPage + 1):
        pn = (page - 1) * 50
        filename = "第" + str(page) + "页.html"
        print(filename)
        fullurl = url + "&pn=" + str(pn)

        html = loadPage(fullurl,filename)

        writePage(html,filename)
        print("谢谢使用")

if  __name__ =="__main__":
    kw = input("请输入需要爬取得吧名：")
    beginPage = int(input("请输入起始页："))
    endPage  = int(input("请输入结束页："))
    
    url = "http://tieba.baidu.com/f?"
    key = urllib.parse.urlencode({"kw":kw})
    fullurl = url + key 
    tiebaSpider(fullurl, beginPage, endPage)