python-爬取糗事百科热图

此次运用requests和beautifulSoup爬取糗事百科热图，常用的网络库有：urllib，urllib3，requests，选取其中之一就行了；HTML/XML解析器有：lxml，BeautifulSoup，html5lib，selenium，re等。

如果经常爬虫，觉得可以固定选择一种网络库和页面解析器，否则太多了不容易记住，主要思路就是访问页面（网络库）--分析页面元素（可通过浏览区F12查看）--提取需要的数据（页面解析器）。

在爬取的过程中发现，最好headers信息填的全一些，否则会报404错。示例代码：

# -*- coding:utf-8 -*-
from bs4 import BeautifulSoup
import requests
import re
import os

def parseHtml(allPageUrls,headers):
    imgUrls = []
    for i in allPageUrls:
        html = requests.get(i, headers=headers).text
        soup = BeautifulSoup(html, 'lxml').find_all('img', class_="illustration")
        for url in soup:
            #imgUrls.append('http:' + re.findall('src="(\S+)"', str(url))[0])   #也可用正则查找
            imgUrls.append('http:' + url['src'])
    return imgUrls

def downloadImages(urls,path):
    global count
    if not os.path.exists(path):
        print("Download path error!")
        pass
    else:
        path = path.rstrip('/')
    for i in urls:
        count += 1
        img = requests.get(i).content
        with open(path + '//{0}.jpg'.format(count),'wb') as f:
            f.write(img)

def getAllPageUrls(baseUrl,headers):
    allPageUrls = []
    allPageUrls.append(baseUrl)
    html = requests.get(baseUrl, headers=headers).text
    pageNum = BeautifulSoup(html,'lxml').find_all('span',class_='page-numbers')[-1].text.strip()
    for num in range(int(pageNum)):
        if num >= 2:
           allPageUrls.append(baseUrl + 'page/{0}/'.format(num))
    return allPageUrls

def main():
    baseUrl = "https://www.qiushibaike.com/imgrank/"
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:67.0) Gecko/20100101 Firefox/67.0",
        # "Host":"static.qiushibaike.com",
        "Accept": "text/css,*/*;q=0.1",
        "Accept-Encoding": "gzip, deflate, br",
        "Accept-Language": "zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2",
        "Connection": "keep-alive",
        "Cookie": 'Hm_lvt_2670efbdd59c7e3ed3749b458cafaa37=1564111558; Hm_lpvt_2670efbdd59c7e3ed3749b458cafaa37=1564111562; BAIDU_SSP_lcr=https://www.baidu.com/link?url=jWhGNGV5ALzyB_BRJKkXdeb60lmYQ3_Lewk3NHsLe_C9fvNwKDdTPwZDtD2GrY15&wd=&eqid=b4f829d300000e94000000045d3a72c3; _qqq_uuid_="2|1:0|10:1564111558|10:_qqq_uuid_|56:OWQxZTVlNjY4MWY2MjVmOTdjODkwMDE3MTEwZTQ0ZTE2ZGU4NTA1NA==|971036a31548dd5a201f29c949b56990b4895dee0e489693b7b9631f363ca452"; _ga=GA1.2.126854589.1564111558; _gid=GA1.2.839365496.1564111558; _gat=1',
        "TE": "Trailers"
    }
    allPageUrls = getAllPageUrls(baseUrl, headers)  #获取所有页面的访问地址
    allImageUrls = parseHtml(allPageUrls, headers)  #获取所有页面中图片地址
    downloadImages(allImageUrls,'e://qiushibaike')  #下载图片

if __name__ == '__main__':
    count = 0
    main()

运行结果：