Python爬虫的scrapy框架的简单应用

load_mzitu\mzitu\​​item.py​​

# -*- coding: utf-8 -*-
# Define here the models for your scraped items
#
# See documentation in:
# http://doc.scrapy.org/en/latest/topics/items.html

import scrapy


class MzituItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    name=scrapy.Field()
    image_url=scrapy.Field()
    url=scrapy.Field()

load_mzitu\mzitu\​​middlewares.py​​

# -*- coding: utf-8 -*-

# Define here the models for your spider middleware
#
# See documentation in:
# http://doc.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals


class MzituSpiderMiddleware(object):
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, dict or Item objects.
        for i in result:
            yield i

    def process_spider_exception(response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Response, dict
        # or Item objects.
        pass

    def process_start_requests(start_requests, spider):
        # Called with the start requests of the spider, and works
        # similarly to the process_spider_output() method, except
        # that it doesn’t have a response associated.

        # Must return only requests (not items).
        for r in start_requests:
            yield r

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)

#防盗链
class MeiZiTu(object):

    def process_request(self, request, spider):
        '''设置headers和切换请求头
        :param request: 请求体
        :param spider: spider对象
        :return: None
        '''
        referer = request.meta.get('referer', None)
        if referer:
            request.headers['referer'] = referer

load_mzitu\mzitu\​​pipelines.py​​

# -*- coding: utf-8 -*-

# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: http://doc.scrapy.org/en/latest/topics/item-pipeline.html
#图片管道
from scrapy.pipelines.images import ImagesPipeline
from scrapy.exceptions import DropItem
from scrapy import Request
import re
import urllib
import uuid

class MzituPipeline(ImagesPipeline):
    #重写请求
    def get_media_requests(self, item, info):
        """
          :param item: spider.py中返回的item
          :param info:
          :return:
          """
        # 这里的item['image_url'] 是前面的meizi.py返回的一个列表

        for img_url in item['image_url']:
            #这是每一套图总地址url 是前面的meizi.py返回的是一个字符串
            referer=item['url']
            x=uuid.uuid1()
            urllib.urlretrieve(referer,'F:\scrapy\MZITU\%s.jpg' % x)
            #这里的Request默认callback给file_path meta传递参数给 file_path
            yield Request(img_url,meta={'item':item,'referer':referer})

    # 重写文件路径
    def file_path(self, request, response=None, info=None):
        """
           :param request: 每一个图片下载管道请求
           :param response:
           :param info:
           :param strip :清洗Windows系统的文件夹非法字符，避免无法创建目录
           :return: 每套图的分类目录 传递到item_completed的results
           """
        #接收来自get_media_requests的item 也就是meizi.py提交过来的 item
        item=request.meta['item']
        #得到每套图的名字（文件夹名）
        file_name=item['name']
        #因为得到的名字可能存在window系统非法的文件字符串 所以这里替换一下
        file_name=strip(file_name)
        #利用图片url的分割得到每张图片的名字
        img_name=request.url.split('/')[-1]
        #这里是结合起来得到的每一张图片的具体存取路径
        file_img_path='full/{}/{}'.format(file_name,img_name)
        #print file_img_path
        return file_img_path

    def item_completed(self, results, item, info):
        image_paths = [x['path'] for ok, x in results if ok]
        if not image_paths:
            raise DropItem("Item contains no images")
        return item

def strip(path):
    """
    :param path: 需要清洗的文件夹名字
    :return: 清洗掉Windows系统非法文件夹名字的字符串
    """
    #找到 RE 匹配的所有子串，并将其用一个不同的字符串替换。可选参数 count 是模式匹配後替换的最大次数；count 必须是非负整数。
    # 缺省值是 0 表示替换所有的匹配。如果无匹配，字符串将会无改变地返回 re.sub(pattern, repl, string, count=0, flags=0)
    #这里非法字符用空''替换
    path = re.sub(r'[？\\*|“<>:/]','', str(path))
    return path


            # def process_item(self, item, spider):
    #     return item
if __name__=="__main__":
    #没什么意思 测试下strip好不好用
    a = '我是一个？\*|“<>:/错误的字符串'
    print(strip(a))

load_mzitu\mzitu\​​settings.py​​

# -*- coding: utf-8 -*-

# Scrapy settings for mzitu project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     http://doc.scrapy.org/en/latest/topics/settings.html
#     http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
#     http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html

BOT_NAME = 'mzitu'

SPIDER_MODULES = ['mzitu.spiders']
NEWSPIDER_MODULE = 'mzitu.spiders'


# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'mzitu (+http://www.yourdomain.com)'

# Obey robots.txt rules
ROBOTSTXT_OBEY = False

# Configure maximum concurrent requests performed by Scrapy (default: 16)
#CONCURRENT_REQUESTS = 32

# Configure a delay for requests for the same website (default: 0)
# See http://scrapy.readthedocs.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
#DOWNLOAD_DELAY = 3
# The download delay setting will honor only one of:
#CONCURRENT_REQUESTS_PER_DOMAIN = 16
#CONCURRENT_REQUESTS_PER_IP = 16

# Disable cookies (enabled by default)
#COOKIES_ENABLED = False

# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_ENABLED = False

# Override the default request headers:
#DEFAULT_REQUEST_HEADERS = {
#   'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
#   'Accept-Language': 'en',
#}

# Enable or disable spider middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'mzitu.middlewares.MzituSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES = {
    'mzitu.middlewares.MeiZiTu':5,
}

# Enable or disable extensions
# See http://scrapy.readthedocs.org/en/latest/topics/extensions.html
#EXTENSIONS = {
#    'scrapy.extensions.telnet.TelnetConsole': None,
#}

# Configure item pipelines
# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES = {
    'mzitu.pipelines.MzituPipeline': 1.7,
}
IMAGES_STORE = 'F:/scrapy/load_mzitu/mztu'
# 30 days of delay for images expiration
IMAGES_EXPIRES = 10
# Enable and configure the AutoThrottle extension (disabled by default)
# See http://doc.scrapy.org/en/latest/topics/autothrottle.html
#AUTOTHROTTLE_ENABLED = True
# The initial download delay
#AUTOTHROTTLE_START_DELAY = 5
# The maximum download delay to be set in case of high latencies
#AUTOTHROTTLE_MAX_DELAY = 60
# The average number of requests Scrapy should be sending in parallel to
# each remote server
#AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
# Enable showing throttling stats for every response received:
#AUTOTHROTTLE_DEBUG = False

# Enable and configure HTTP caching (disabled by default)
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
#HTTPCACHE_ENABLED = True
#HTTPCACHE_EXPIRATION_SECS = 0
#HTTPCACHE_DIR = 'httpcache'
#HTTPCACHE_IGNORE_HTTP_CODES = []
#HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'

load_mzitu\mzitu\spiders\meizi .py

# -*- coding: utf-8 -*-
import scrapy

from mzitu.items import MzituItem
from scrapy.spiders import CrawlSpider,Rule
from scrapy.linkextractors import LinkExtractor
###这里千万要把parser函数删了 不然无法调用parser_item函数 因为CrawlSpider已经默认使用parser函数来爬取第一个链接
#该程序的目的就是找到所有的符合规律的url链接跟进获取图片
class MeiziSpider(CrawlSpider):
    name = "meizi"
    allowed_domains = ["mzitu.com"]
    start_urls = ['http://www.mzitu.com/']
    #定义一个全局的列表
    img_urls=[]
    #定义抓取规则 找到如下规则内的所有url allow是允许的  deny是不允许的 从start_url页，从start_urls链接的源代码开始找 然后再跟进继续使用该规则
    rules = (
        Rule(LinkExtractor(allow=('http://www.mzitu.com/\d{6}',),deny=('http://www.mzitu.com/\s',)),\
             callback='parser_item',follow=True),
           )

    def parser_item(self,response):
        item=MzituItem()
        #得到没套图的名字 extract_first(default=”N/A”)取xpath返回值的第一个元素。如果xpath没有取到值，则返回N/A
        #这里我用字符串分割的方法
        name=response.selector.xpath('/html/body/div[2]/div[1]/div[1]/text()[3]').extract()
        item['name']=name[0][3:-1]
        item['url']=response.url
        all_page=response.selector.xpath('/html/body/div[2]/div[1]/div[4]/a[5]/span/text()').extract()
        for page in range(1,int(all_page[0])+1):
            #得到每张照片的地址
            url=response.url+'/'+str(page)
            yield scrapy.Request(url=url,callback=self.img_url)
        #上面的循环所有页面执行完 定义的图片url列表也在下面的 img_url函数里添加好了 所以放入容器
        item['image_url']=self.img_urls
        yield item
    def img_url(self,response):
        urls=response.selector.xpath('/html/body/div[2]/div[1]/div[3]/p/a/img/@src').extract()
        #有的页面不只一张图 所以加个循环 得到当前页面所有的
        print "--------------------------------------------------\n"
        for img_url in urls:
            #x=uuid.uuid1()
            f =open("data.txt","a+")
            f.write(img_url+"\n")
            f.close()
            print img_url+"    ===>>download"
            self.img_urls.append(img_url)

load_mzitu\​​begin.py​​

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2017/10/30 19:28
# @Author  : Yu
# @Site    : 
# @File    : begin.py
from scrapy import cmdline
cmdline.execute(["scrapy","crawl","meizi"])

#http://i.meizitu.net/2015/05/29m02.jpg
#http://www.mzitu.com/156427

运行begin后会把所有爬取到的图片链接写入到txt中

load_mzitu\​​download.py​​

import urllib 
import urllib2 
import requests
import random 
import uuid,os


#img_url = "https://p.ssl.qhimg.com/dm/48_48_100/t017aee03b28107657b.jpg"

img_url="http://i.meizitu.net/2018/10/13c02.jpg"
img="http://i.meizitu.net/2018/11/06c35.jpg"

my_headers={
    "User-Agent":"Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Mobile Safari/537.36",
   'Referer':'http://m.mzitu.com/15309'}

def read_txt(path):
    mt=[]
    f=open(path,'r')
    for t in f.readlines():
        mt.append(t)
    f.close()
    return mt
 
def down_load(img,my_headers):
    request =  urllib2.Request(url=img, headers=my_headers)
    response = urllib2.urlopen(request)
    pic=response.read()
    path_name=img.split('/')[-1]
    path_name=path_name.replace('\n','')
    new_name="pic/" + path_name
    
    if not os.path.exists(new_name):
        with open("%s" % new_name, "wb") as f:
            f.write(pic)
        
    print "downloading with urllib"
    
def main():
    path="data.txt"
    mt=read_txt(path)
    print len(mt)
    print len(set(mt))
    for f in mt:
        print f
        down_load(f,my_headers)
    print 'fininsh'.center(40,'-')
    
main()

运行它会把txt中的图片下载到本地。

详情看​​gittup​​