python爬虫开发之使用Python爬虫库requests多线程抓取猫眼电影TOP100实例

使用Python爬虫库requests多线程抓取猫眼电影TOP100思路：

1. 查看网页源代码
2. 抓取单页内容
3. 正则表达式提取信息
4. 猫眼TOP100所有信息写入文件
5. 多线程抓取

• 运行平台：windows
• Python版本：Python 3.7.
• IDE:Sublime Text
• 浏览器：Chrome浏览器

1.查看猫眼电影TOP100网页原代码

按F12查看网页源代码发现每一个电影的信息都在“<dd></dd>”标签之中。

点开之后，信息如下：

2.抓取单页内容

在浏览器中打开猫眼电影网站，点击“榜单”，再点击“TOP100榜”如下图：

接下来通过以下代码获取网页源代码：

#-*-coding:utf-8-*-
import requests
from requests.exceptions import RequestException

#猫眼电影网站有反爬虫措施，设置headers后可以爬取
headers = {
	'Content-Type': 'text/plain; charset=UTF-8',
	'Origin':'https://maoyan.com',
	'Referer':'https://maoyan.com/board/4',
	'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36'
	}

#爬取网页源代码
def get_one_page(url,headers):
	try:
		response =requests.get(url,headers =headers)
		if response.status_code == 200:
			return response.text
		return None
	except RequestsException:
		return None

def main():
	url = "https://maoyan.com/board/4"
	html = get_one_page(url,headers)
	print(html)

if __name__ == '__main__':
	main()

执行结果如下：

3.正则表达式提取信息

上图标示信息即为要提取的信息，代码实现如下：

#-*-coding:utf-8-*-
import requests
import re
from requests.exceptions import RequestException

#猫眼电影网站有反爬虫措施，设置headers后可以爬取
headers = {
	'Content-Type': 'text/plain; charset=UTF-8',
	'Origin':'https://maoyan.com',
	'Referer':'https://maoyan.com/board/4',
	'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36'
	}

#爬取网页源代码
def get_one_page(url,headers):
	try:
		response =requests.get(url,headers =headers)
		if response.status_code == 200:
			return response.text
		return None
	except RequestsException:
		return None

#正则表达式提取信息
def parse_one_page(html):
	pattern = re.compile('<dd>.*?board-index.*?>(\d+)</i>.*?data-src="(.*?)".*?name"><a'
		+'.*?>(.*?)</a>.*?star">(.*?)</p>.*?releasetime">(.*?)</p>.*?integer">(.*?)</i>.*?fraction">(.*?)</i>.*?</dd>',re.S)
	items = re.findall(pattern,html)
	for item in items:
		yield{
		'index':item[0],
		'image':item[1],
		'title':item[2],
		'actor':item[3].strip()[3:],
		'time':item[4].strip()[5:],
		'score':item[5]+item[6]
		}

def main():
	url = "https://maoyan.com/board/4"
	html = get_one_page(url,headers)
	for item in parse_one_page(html):
		print(item)

if __name__ == '__main__':
	main()

执行结果如下：

4.猫眼TOP100所有信息写入文件

上边代码实现单页的信息抓取，要想爬取100个电影的信息，先观察每一页url的变化，点开每一页我们会发现url进行变化，原url后面多了‘？offset=0',且offset的值变化从0,10,20，变化如下：

代码实现如下：

#-*-coding:utf-8-*-
import requests
import re
import json
import os
from requests.exceptions import RequestException

#猫眼电影网站有反爬虫措施，设置headers后可以爬取
headers = {
	'Content-Type': 'text/plain; charset=UTF-8',
	'Origin':'https://maoyan.com',
	'Referer':'https://maoyan.com/board/4',
	'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36'
	}

#爬取网页源代码
def get_one_page(url,headers):
	try:
		response =requests.get(url,headers =headers)
		if response.status_code == 200:
			return response.text
		return None
	except RequestsException:
		return None

#正则表达式提取信息
def parse_one_page(html):
	pattern = re.compile('<dd>.*?board-index.*?>(\d+)</i>.*?data-src="(.*?)".*?name"><a'
		+'.*?>(.*?)</a>.*?star">(.*?)</p>.*?releasetime">(.*?)</p>.*?integer">(.*?)</i>.*?fraction">(.*?)</i>.*?</dd>',re.S)
	items = re.findall(pattern,html)
	for item in items:
		yield{
		'index':item[0],
		'image':item[1],
		'title':item[2],
		'actor':item[3].strip()[3:],
		'time':item[4].strip()[5:],
		'score':item[5]+item[6]
		}
#猫眼TOP100所有信息写入文件
def write_to_file(content):
	#encoding ='utf-8',ensure_ascii =False,使写入文件的代码显示为中文
	with open('result.txt','a',encoding ='utf-8') as f:
		f.write(json.dumps(content,ensure_ascii =False)+'\n')
		f.close()
#下载电影封面
def save_image_file(url,path):

	jd = requests.get(url)
	if jd.status_code == 200:
		with open(path,'wb') as f:
			f.write(jd.content)
			f.close()

def main(offset):
	url = "https://maoyan.com/board/4?offset="+str(offset)
	html = get_one_page(url,headers)
	if not os.path.exists('covers'):
		os.mkdir('covers')
	for item in parse_one_page(html):
		print(item)
		write_to_file(item)
		save_image_file(item['image'],'covers/'+item['title']+'.jpg')

if __name__ == '__main__':
	#对每一页信息进行爬取
	for i in range(10):
		main(i*10)

爬取结果如下：

5.多线程抓取

进行比较，发现多线程爬取时间明显较快：

多线程：

以下为完整代码：

#-*-coding:utf-8-*-
import requests
import re
import json
import os
from requests.exceptions import RequestException
from multiprocessing import Pool
#猫眼电影网站有反爬虫措施，设置headers后可以爬取
headers = {
	'Content-Type': 'text/plain; charset=UTF-8',
	'Origin':'https://maoyan.com',
	'Referer':'https://maoyan.com/board/4',
	'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36'
	}

#爬取网页源代码
def get_one_page(url,headers):
	try:
		response =requests.get(url,headers =headers)
		if response.status_code == 200:
			return response.text
		return None
	except RequestsException:
		return None

#正则表达式提取信息
def parse_one_page(html):
	pattern = re.compile('<dd>.*?board-index.*?>(\d+)</i>.*?data-src="(.*?)".*?name"><a'
		+'.*?>(.*?)</a>.*?star">(.*?)</p>.*?releasetime">(.*?)</p>.*?integer">(.*?)</i>.*?fraction">(.*?)</i>.*?</dd>',re.S)
	items = re.findall(pattern,html)
	for item in items:
		yield{
		'index':item[0],
		'image':item[1],
		'title':item[2],
		'actor':item[3].strip()[3:],
		'time':item[4].strip()[5:],
		'score':item[5]+item[6]
		}
#猫眼TOP100所有信息写入文件
def write_to_file(content):
	#encoding ='utf-8',ensure_ascii =False,使写入文件的代码显示为中文
	with open('result.txt','a',encoding ='utf-8') as f:
		f.write(json.dumps(content,ensure_ascii =False)+'\n')
		f.close()
#下载电影封面
def save_image_file(url,path):

	jd = requests.get(url)
	if jd.status_code == 200:
		with open(path,'wb') as f:
			f.write(jd.content)
			f.close()

def main(offset):
	url = "https://maoyan.com/board/4?offset="+str(offset)
	html = get_one_page(url,headers)
	if not os.path.exists('covers'):
		os.mkdir('covers')
	for item in parse_one_page(html):
		print(item)
		write_to_file(item)
		save_image_file(item['image'],'covers/'+item['title']+'.jpg')

if __name__ == '__main__':
	#对每一页信息进行爬取
	pool = Pool()
	pool.map(main,[i*10 for i in range(10)])
	pool.close()
	pool.join()

本文主要讲解了使用Python爬虫库requests多线程抓取猫眼电影TOP100数据的实例,更多关于Python爬虫库的知识请查看下面的相关链接