第二十节：Scrapy爬虫框架之使用Pipeline存储

在上两节当中，我们爬取了360图片，但是我们需要将图片下载下来，这将如何下载和存储呢？

下边叙述一下三种情况：1、将图片下载后存储到MongoDB数据库；2、将图片下载后存储在MySQL数据库；3、将图片下载到本地文件

话不多说，直接上代码：

1、通过item定义存储字段

 1 # item.py
 2 import scrapy
 3 
 4 class Bole_mode(scrapy.Item):
 5     collection = "images"     # collection为MongoDB储表名名称
 6     table = "images"           # table为MySQL的存储表名名称
 7     id    = scrapy.Field()      # id
 8     url   = scrapy.Field()      # 图片链接
 9     title = scrapy.Field()      # 标题
10     thumb = scrapy.Field()  # 缩略图

2、配置settings文件获取数据库信息

  1 # -*- coding: utf-8 -*-
  2 
  3 # Scrapy settings for bole project
  4 #
  5 # For simplicity, this file contains only settings considered important or
  6 # commonly used. You can find more settings consulting the documentation:
  7 #
  8 #     https://doc.scrapy.org/en/latest/topics/settings.html
  9 #     https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
 10 #     https://doc.scrapy.org/en/latest/topics/spider-middleware.html
 11 
 12 BOT_NAME = 'bole'
 13 
 14 SPIDER_MODULES = ['BLZX.spiders']
 15 NEWSPIDER_MODULE = 'BLZX.spiders'
 16 
 17 
 18 # Crawl responsibly by identifying yourself (and your website) on the user-agent
 19 #USER_AGENT = 'bole (+http://www.yourdomain.com)'
 20 
 21 # Obey robots.txt rules
 22 ROBOTSTXT_OBEY = False
 23 USER_AGENT = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.54 Safari/536.5'
 24 
 25 # Configure maximum concurrent requests performed by Scrapy (default: 16)
 26 #CONCURRENT_REQUESTS = 32
 27 
 28 # Configure a delay for requests for the same website (default: 0)
 29 # See https://doc.scrapy.org/en/latest/topics/settings.html#download-delay
 30 # See also autothrottle settings and docs
 31 #DOWNLOAD_DELAY = 3
 32 # The download delay setting will honor only one of:
 33 #CONCURRENT_REQUESTS_PER_DOMAIN = 16
 34 #CONCURRENT_REQUESTS_PER_IP = 16
 35 
 36 # Disable cookies (enabled by default)
 37 #COOKIES_ENABLED = False
 38 
 39 # Disable Telnet Console (enabled by default)
 40 #TELNETCONSOLE_ENABLED = False
 41 
 42 # Override the default request headers:
 43 #DEFAULT_REQUEST_HEADERS = {
 44 #   'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
 45 #   'Accept-Language': 'en',
 46 #}
 47 
 48 # Enable or disable spider middlewares
 49 # See https://doc.scrapy.org/en/latest/topics/spider-middleware.html
 50 #SPIDER_MIDDLEWARES = {
 51 #    'bole.middlewares.BoleSpiderMiddleware': 543,
 52 #}
 53 
 54 # Enable or disable downloader middlewares
 55 # See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
 56 
 57 
 58 # DOWNLOADER_MIDDLEWARES = {
 59 #    'scrapy.contrib.downloadermiddleware.httpproxy.HttpProxyMiddleware':None,
 60 #    'bole.middlewares.ProxyMiddleware':125,
 61 #    'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware':None
 62 # }
 63 
 64 
 65 
 66 # Enable or disable extensions
 67 # See https://doc.scrapy.org/en/latest/topics/extensions.html
 68 #EXTENSIONS = {
 69 #    'scrapy.extensions.telnet.TelnetConsole': None,
 70 #}
 71 
 72 
 73 # Configure item pipelines
 74 # See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
 75 ITEM_PIPELINES = {
 76     "bole.pipelines.BoleImagePipeline":2,
 77     "bole.pipelines.ImagePipeline":300,
 78     "bole.pipelines.MongoPipeline":301,
 79     "bole.pipelines.MysqlPipeline":302,
 80 }
 81 
 82 
 83 # Enable and configure the AutoThrottle extension (disabled by default)
 84 # See https://doc.scrapy.org/en/latest/topics/autothrottle.html
 85 #AUTOTHROTTLE_ENABLED = True
 86 # The initial download delay
 87 #AUTOTHROTTLE_START_DELAY = 5
 88 # The maximum download delay to be set in case of high latencies
 89 #AUTOTHROTTLE_MAX_DELAY = 60
 90 # The average number of requests Scrapy should be sending in parallel to
 91 # each remote server
 92 #AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
 93 # Enable showing throttling stats for every response received:
 94 #AUTOTHROTTLE_DEBUG = False
 95 
 96 # Enable and configure HTTP caching (disabled by default)
 97 # See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
 98 #HTTPCACHE_ENABLED = True
 99 #HTTPCACHE_EXPIRATION_SECS = 0
100 #HTTPCACHE_DIR = 'httpcache'
101 #HTTPCACHE_IGNORE_HTTP_CODES = []
102 #HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'
103 
104 
105 # 爬取最大页数
106 MAX_PAGE = 50
107 
108 # mongodb配置
109 MONGODB_URL = "localhost"
110 MONGODB_DB = "Images360"
111 
112 # MySQL配置
113 MYSQL_HOST = "localhost"
114 MYSQL_DATABASE = "images360"
115 MYSQL_PORT = 3306
116 MYSQL_USER = "root"
117 MYSQL_PASSWORD = "123456"
118 
119 # 本地配置
120 IMAGES_STORE = r"D:spideroleimage"

3、此处的Middlewares没有做任何修改

  1 # -*- coding: utf-8 -*-
  2 
  3 # Define here the models for your spider middleware
  4 #
  5 # See documentation in:
  6 # https://doc.scrapy.org/en/latest/topics/spider-middleware.html
  7 
  8 from scrapy import signals
  9 
 10 
 11 class BoleSpiderMiddleware(object):
 12     # Not all methods need to be defined. If a method is not defined,
 13     # scrapy acts as if the spider middleware does not modify the
 14     # passed objects.
 15 
 16     @classmethod
 17     def from_crawler(cls, crawler):
 18         # This method is used by Scrapy to create your spiders.
 19         s = cls()
 20         crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
 21         return s
 22 
 23     def process_spider_input(self, response, spider):
 24         # Called for each response that goes through the spider
 25         # middleware and into the spider.
 26 
 27         # Should return None or raise an exception.
 28         return None
 29 
 30     def process_spider_output(self, response, result, spider):
 31         # Called with the results returned from the Spider, after
 32         # it has processed the response.
 33 
 34         # Must return an iterable of Request, dict or Item objects.
 35         for i in result:
 36             yield i
 37 
 38     def process_spider_exception(self, response, exception, spider):
 39         # Called when a spider or process_spider_input() method
 40         # (from other spider middleware) raises an exception.
 41 
 42         # Should return either None or an iterable of Response, dict
 43         # or Item objects.
 44         pass
 45 
 46     def process_start_requests(self, start_requests, spider):
 47         # Called with the start requests of the spider, and works
 48         # similarly to the process_spider_output() method, except
 49         # that it doesn’t have a response associated.
 50 
 51         # Must return only requests (not items).
 52         for r in start_requests:
 53             yield r
 54 
 55     def spider_opened(self, spider):
 56         spider.logger.info('Spider opened: %s' % spider.name)
 57 
 58 
 59 class BoleDownloaderMiddleware(object):
 60     # Not all methods need to be defined. If a method is not defined,
 61     # scrapy acts as if the downloader middleware does not modify the
 62     # passed objects.
 63 
 64     @classmethod
 65     def from_crawler(cls, crawler):
 66         # This method is used by Scrapy to create your spiders.
 67         s = cls()
 68         crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
 69         return s
 70 
 71     def process_request(self, request, spider):
 72         # Called for each request that goes through the downloader
 73         # middleware.
 74 
 75         # Must either:
 76         # - return None: continue processing this request
 77         # - or return a Response object
 78         # - or return a Request object
 79         # - or raise IgnoreRequest: process_exception() methods of
 80         #   installed downloader middleware will be called
 81         return None
 82 
 83     def process_response(self, request, response, spider):
 84         # Called with the response returned from the downloader.
 85 
 86         # Must either;
 87         # - return a Response object
 88         # - return a Request object
 89         # - or raise IgnoreRequest
 90         return response
 91 
 92     def process_exception(self, request, exception, spider):
 93         # Called when a download handler or a process_request()
 94         # (from other downloader middleware) raises an exception.
 95 
 96         # Must either:
 97         # - return None: continue processing this exception
 98         # - return a Response object: stops process_exception() chain
 99         # - return a Request object: stops process_exception() chain
100         pass
101 
102     def spider_opened(self, spider):
103         spider.logger.info('Spider opened: %s' % spider.name)

View Code

4、通过Pipeline对爬取的数据进行存储，分为MongoDB数据库存储，MySQL数据库存储，本地文件夹存储

 1 # -*- coding: utf-8 -*-
 2 # ==========================MongoDB===========================
 3 import pymongo
 4 class MongoPipeline(object):
 5     def __init__(self,mongodb_url,mongodb_DB):
 6         self.mongodb_url = mongodb_url
 7         self.mongodb_DB = mongodb_DB
 8 
 9     @classmethod
10     # 获取settings配置文件当中设置的MONGODB_URL和MONGODB_DB
11     def from_crawler(cls,crawler):
12         return cls(
13                     mongodb_url=crawler.settings.get("MONGODB_URL"),
14                     mongodb_DB=crawler.settings.get("MONGODB_DB")
15                    )
16 
17     # 开启爬虫时连接MongoDB数据库
18     def open_spider(self,spider):
19         self.client = pymongo.MongoClient(self.mongodb_url)
20         self.db = self.client[self.mongodb_DB]
21 
22     def process_item(self,item,spider):
23         table_name = item.collection
24         self.db[table_name].insert(dict(item))
25         return item
26 
27     # 关闭爬虫时断开MongoDB数据库连接
28     def close_spider(self,spider):
29         self.client.close()
30 
31 
32 # ============================MySQL===========================
33 import pymysql
34 class MysqlPipeline():
35     def __init__(self,host,database,port,user,password):
36         self.host = host
37         self.database = database
38         self.port = port
39         self.user = user
40         self.password = password
41 
42     @classmethod
43     # 获取settings配置文件当中设置的MySQL各个参数
44     def from_crawler(cls,crawler):
45         return cls(
46             host=crawler.settings.get("MYSQL_HOST"),
47             database=crawler.settings.get("MYSQL_DATABASE"),
48             port=crawler.settings.get("MYSQL_PORT"),
49             user=crawler.settings.get("MYSQL_USER"),
50             password=crawler.settings.get("MYSQL_PASSWORD")
51         )
52 
53     # 开启爬虫时连接MongoDB数据库
54     def open_spider(self,spider):
55         self.db = pymysql.connect(host=self.host,database=self.database,user=self.user,password=self.password,port=self.port,charset="utf8")
56         self.cursor = self.db.cursor()
57 
58     def process_item(self,item,spider):
59         data = dict(item)
60         keys = ",".join(data.keys())            # 字段名
61         values =",".join(["%s"]*len(data))     # 值
62         sql = "insert into %s(%s) values(%s)"%(item.table, keys, values)
63         self.cursor.execute(sql, tuple(data.values()))
64         self.db.commit()
65         return item
66 
67     # 关闭爬虫时断开MongoDB数据库连接
68     def close_spider(self,spider):
69         self.db.close()
70 
71 
72 
73 # # ============================本地===========================
74 import scrapy
75 from scrapy.exceptions import DropItem
76 from scrapy.pipelines.images import ImagesPipeline
77 
78 class ImagePipeline(ImagesPipeline):
79 
80     # 由于item里的url不是list，所以重写下面几个函数
81     def file_path(self, request, response=None, info=None):
82         url = request.url
83         file_name = url.split("/")[-1]    # 将url连接的最后一部分作为文件名称
84         return file_name
85 
86     # results为item对应的图片下载的结果，他是一个list，每个元素为元组，并包含了下载成功和失败的信息
87     def item_completed(self, results, item, info):
88 
89         # 获取图片地址path
90         image_paths = [x["path"] for ok,x in results if ok]
91         if not image_paths:
92             raise DropItem("图片下载失败！！")
93         return item
94 
95     def get_media_requests(self, item, info):
96 
97         # 获取item文件里的url字段并加入队列等待被调用进行下载图片
98         yield scrapy.Request(item["url"])

5、最后就是spider数据爬取了

 1 import scrapy
 2 import json
 3 import sys
 4 
 5 sys.path.append(r'D:spideroleitem.py')
 6 from bole.items import Bole_mode
 7 
 8 class BoleSpider(scrapy.Spider):
 9     name = 'boleSpider'
10 
11     def start_requests(self):
12         url = "https://image.so.com/zj?ch=photography&sn={}&listtype=new&temp=1"
13         page = self.settings.get("MAX_PAGE")
14         for i in range(int(page)+1):
15             yield scrapy.Request(url=url.format(i*30))
16 
17     def parse(self,response):
18         photo_list = json.loads(response.text)
19         item  = Bole_mode()
20         for image in photo_list.get("list"):
21             item["id"] = image["id"]
22             item["url"] = image["qhimg_url"]
23             item["title"] = image["group_title"]
24             item["thumb"] = image["qhimg_thumb_url"]
25             yield item

6、最最后就是对爬取的结果展示一下呗（只展示MySQL和本地，MongoDB没打开）

（1） MySQL存储

（2）本地存储