Scrapy爬虫实例——校花网

学习爬虫有一段时间了，今天使用Scrapy框架将校花网的图片爬取到本地。Scrapy爬虫框架相对于使用requests库进行网页的爬取，拥有更高的性能。

Scrapy官方定义：Scrapy是用于抓取网站并提取结构化数据的应用程序框架，可用于广泛的有用应用程序，如数据挖掘，信息处理或历史存档。

建立Scrapy爬虫工程

在安装好Scrapy框架后，直接使用命令行进行项目的创建：

E:ScrapyDemo>scrapy startproject xiaohuar
New Scrapy project 'xiaohuar', using template directory 'c:\users\lei\appdata\local\programs\python\python35\lib
\site-packages\scrapy\templates\project', created in:
    E:ScrapyDemoxiaohuar

You can start your first spider with:
    cd xiaohuar
    scrapy genspider example example.com

创建一个Scrapy爬虫

创建工程的时候，会自动创建一个与工程同名的目录，进入到目录中执行如下命令：

E:ScrapyDemoxiaohuar>scrapy genspider -t basic xiaohua xiaohuar.com
Created spider 'xiaohua' using template 'basic' in module:
  xiaohuar.spiders.xiaohua

命令中"xiaohua"是生成Spider中*.py文件的文件名，"xiaohuar.com"是将要爬取网站的URL，可以在程序中更改。

编写Spider代码

编写E:ScrapyDemoxiaohuarxiaohuarspiders中的xiaohua.py文件。主要是配置URL和对请求到的页面的解析方式。

# -*- coding: utf-8 -*-
import scrapy
from scrapy.http import Request
import re

class XiaohuaSpider(scrapy.Spider):
    name = 'xiaohua'
    allowed_domains = ['xiaohuar.com']
    start_urls = []
    for i in range(43):
        url = "http://www.xiaohuar.com/list-1-%s.html" %i
        start_urls.append(url)

    def parse(self, response):
        if "www.xiaohuar.com/list-1" in response.url:
            # 下载的html源代码
            html = response.text
            # 网页中图片存储地址：src="/d/file/20160126/905e563421921adf9b6fb4408ec4e72f.jpg"
            # 通过正则匹配到所有的图片
            # 获取的是图片的相对路径的列表
            img_urls = re.findall(r'/d/file/d+/w+.jpg',html)
            
            # 使用循环对图片页进行请求
            for img_url in img_urls:
                # 将图片的URL补全
                if "http://" not in img_url:
                    img_url = "http://www.xiaohuar.com%s" %img_url
                
                # 回调，返回response
                yield Request(img_url)
        else:
            # 下载图片 
            url = response.url
            # 保存的图片文件名
            title = re.findall(r'w*.jpg',url)[0]
            # 保存图片
            with open('E:\xiaohua_img\%s' % title, 'wb') as f:
                f.write(response.body)

这里使用正则表达式对图片的地址进行匹配，其他网页也都大同小异，需要根据具体的网页源代码进行分析。

运行爬虫

E:ScrapyDemoxiaohuar>scrapy crawl xiaohua
2017-10-22 22:30:11 [scrapy.utils.log] INFO: Scrapy 1.4.0 started (bot: xiaohuar)
2017-10-22 22:30:11 [scrapy.utils.log] INFO: Overridden settings: {'BOT_NAME': 'xiaohuar', 'SPIDER_MODULES': ['xiaohuar.
spiders'], 'ROBOTSTXT_OBEY': True, 'NEWSPIDER_MODULE': 'xiaohuar.spiders'}
2017-10-22 22:30:11 [scrapy.middleware] INFO: Enabled extensions:
['scrapy.extensions.telnet.TelnetConsole',
 'scrapy.extensions.corestats.CoreStats',
 'scrapy.extensions.logstats.LogStats']
2017-10-22 22:30:12 [scrapy.middleware] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2017-10-22 22:30:12 [scrapy.middleware] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2017-10-22 22:30:12 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2017-10-22 22:30:12 [scrapy.core.engine] INFO: Spider opened
2017-10-22 22:30:12 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min
)
2017-10-22 22:30:12 [scrapy.extensions.telnet] DEBUG: Telnet console listening on 127.0.0.1:6023
2017-10-22 22:30:12 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/robots.txt> (referer: None)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/list-1-0.html> (referer: None
)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170721/cb96f1b106b3d
b4a6bfcf3d2e880dea0.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170824/dcc166b0eba6a
37e05424cfc29023121.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170916/7f78145b1ca16
2eb814fbc03ad24fbc1.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170919/2f728d0f110a2
1fea95ce13e0b010d06.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170819/9c3dfeef7e08c
c0303ce233e4ddafa7f.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170917/715515e7fe1f1
cb9fd388bbbb00467c2.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170628/f3d06ef49965a
edbe18286a2f221fd9f.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170513/6121e3e90ff3b
a4c9398121bda1dd582.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170516/6e295fe48c332
45be858c40d37fb5ee6.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170707/f7ca636f73937
e33836e765b7261f036.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170528/b352258c83776
b9a2462277dec375d0c.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170527/4a7a7f1e6b69f
126292b981c90110d0a.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170715/61110ba027f00
4fb503ff09cdee44d0c.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170520/dd21a21751e24
a8f161792b66011688c.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170529/8140c4ad797ca
01f5e99d09c82dd8a42.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170603/e55f77fb3aa3c
7f118a46eeef5c0fbbf.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170529/e5902d4d3e408
29f9a0d30f7488eab84.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170604/ec3794d0d42b5
38bf4461a84dac32509.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170603/c34b29f68e8f9
6d44c63fe29bf4a66b8.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170701/fb18711a6af87
f30942d6a19f6da6b3e.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170619/e0456729d4dcb
ea569a1acbc6a47ab69.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.xiaohuar.com/d/file/20170626/0ab1d89f54c90
df477a90aa533ceea36.jpg> (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] INFO: Closing spider (finished)
2017-10-22 22:30:15 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 8785,
 'downloader/request_count': 24,
 'downloader/request_method_count/GET': 24,
 'downloader/response_bytes': 2278896,
 'downloader/response_count': 24,
 'downloader/response_status_count/200': 24,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2017, 10, 22, 14, 30, 15, 892287),
 'log_count/DEBUG': 25,
 'log_count/INFO': 7,
 'request_depth_max': 1,
 'response_received_count': 24,
 'scheduler/dequeued': 23,
 'scheduler/dequeued/memory': 23,
 'scheduler/enqueued': 23,
 'scheduler/enqueued/memory': 23,
 'start_time': datetime.datetime(2017, 10, 22, 14, 30, 12, 698874)}
2017-10-22 22:30:15 [scrapy.core.engine] INFO: Spider closed (finished)

图片保存

在图片保存过程中""需要进行转义。

>>> import requests
>>> r = requests.get("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1508693697147&di=23eb655d8e450f84cf39453bc1029bc0&imgtype=0&src=http%3A%2F%2Fb.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2Fc9fcc3cec3fdfc038b027f7bde3f8794a5c226fe.jpg")
>>> open("E:xiaohua_img1.jpg",'wb').write(r.content)
  File "<stdin>", line 1
SyntaxError: (unicode error) 'unicodeescape' codec can't decode by
>>> open("E:\xiaohua_img1.jpg",'wb').write(r.content)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: [Errno 22] Invalid argument: 'E:\xiaohua_imgx01.jpg'
>>> open("E:\xiaohua_img\1.jpg",'wb').write(r.content)
34342