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:\ScrapyDemo\xiaohuar 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:\ScrapyDemo\xiaohuar>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:\ScrapyDemo\xiaohuar\xiaohuar\spiders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:\ScrapyDemo\xiaohuar>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) (referer: None)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) (referer: None
)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:13 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:14 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (referer: http://www.xiaohuar.com/list-1-0.html)
2017-10-22 22:30:15 [scrapy.core.engine] DEBUG: Crawled (200) (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)
scrapy crawl xiaohua
图片保存
在图片保存过程中"\"需要进行转义。
>>> 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_img\01.jpg",'wb').write(r.content)
File "", line 1
SyntaxError: (unicode error) 'unicodeescape' codec can't decode by
>>> open("E:\\xiaohua_img\1.jpg",'wb').write(r.content)
Traceback (most recent call last):
File "", line 1, in
OSError: [Errno 22] Invalid argument: 'E:\\xiaohua_img\x01.jpg'
>>> open("E:\\xiaohua_img\\1.jpg",'wb').write(r.content)
以上这篇Scrapy爬虫实例讲解_校花网就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持脚本之家。