31.网站数据监控-2（scrapy文件下载）

温州数据采集

这里采集网站数据是下载pdf：http://wzszjw.wenzhou.gov.cn/col/col1357901/index.html
（涉及的问题就是scrapy 文件的下载设置，之前没用scrapy下载文件，所以弄了很久才弄好，网上很多不过写的都不完善。）

主要重点就是设置： 

1.piplines.py  文件下载代码 这部分可以直接拿来用不需要修改。

2.就是下载文件的url要放在列表里   item['file_urls']=[url]（wenzhou.py）

3. setting.py 主要配置 

ITEM_PIPELINES = {
    'wenzhou_web.pipelines.WenzhouWebPipeline': 300,
    # 下载文件管道
    'scrapy.pipelines.MyFilePipeline': 1,
}
#下载路径
FILES_STORE = './download'

4.下载的文件就会保存到download文件夹中
如图：

wenzhou.py

# -*- coding: utf-8 -*-
import scrapy
import re
from wenzhou_web.items import WenzhouWebItem
class WenzhouSpider(scrapy.Spider):
    name = 'wenzhou'
    base_url=['http://wzszjw.wenzhou.gov.cn']
    allowed_domains = ['wzszjw.wenzhou.gov.cn']
    start_urls = ['http://wzszjw.wenzhou.gov.cn/col/col1357901/index.html']
    custom_settings = {
        "DOWNLOAD_DELAY": 0.5,
        "ITEM_PIPELINES": {
            'wenzhou_web.pipelines.MysqlPipeline': 320,
            'wenzhou_web.pipelines.MyFilePipeline': 321,
        },
        "DOWNLOADER_MIDDLEWARES": {
            'wenzhou_web.middlewares.WenzhouWebDownloaderMiddleware': 500,
        },
    }

    def parse(self, response):
        _response=response.text
        tag_list=re.findall("<span>.*?</span><b>&middot;</b><a href=\'(.*?)\'",_response)
        for tag in tag_list:
            url=self.base_url[0]+tag
            # print(url)
            yield scrapy.Request(url=url,callback=self.parse_detail)

    def parse_detail(self,response):
        # _response=response.text.encode('utf8')
        # print(_response)
        _response=response.text

        item=WenzhouWebItem()

        pdf_url=re.findall(r'<a target="_blank" href="(.*?)"',_response)
        for u in pdf_url:

            u=u.split('pdf')[0]
            # print(u)

            #链接
            url="http://wzszjw.wenzhou.gov.cn"+u+"pdf"
            # print(url)

            item['file_urls']=[url]

            yield item
    #         # #标题
    #         # try:
    #         #     title=re.findall('<img src=".*?".*?><span style=".*?">(.*?)</span></a></p><meta name="ContentEnd">',_response)
    #         #     print(title[0])
    #         # except:
    #         #     print('有异常！')

items.py

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

# Define here the models for your scraped items
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/items.html

import scrapy

class WenzhouWebItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    # pass

    #链接
    file_urls=scrapy.Field()

middlewares.py

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

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

from scrapy import signals

class WenzhouWebSpiderMiddleware(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(self, 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(self, 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(self, 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(self, 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)

class WenzhouWebDownloaderMiddleware(object):
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader 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_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

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

piplines.py

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

# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html

from scrapy.conf import settings
from scrapy.exceptions import DropItem
from scrapy.pipelines.files import FilesPipeline
import pymysql
from urllib.parse import urlparse
import scrapy

class WenzhouWebPipeline(object):
    def process_item(self, item, spider):
        return item

# 数据保存mysql
class MysqlPipeline(object):

    def open_spider(self, spider):
        self.host = settings.get('MYSQL_HOST')
        self.port = settings.get('MYSQL_PORT')
        self.user = settings.get('MYSQL_USER')
        self.password = settings.get('MYSQL_PASSWORD')
        self.db = settings.get(('MYSQL_DB'))
        self.table = settings.get('TABLE')
        self.client = pymysql.connect(host=self.host, user=self.user, password=self.password, port=self.port, db=self.db, charset='utf8')

    def process_item(self, item, spider):
        item_dict = dict(item)
        cursor = self.client.cursor()
        values = ','.join(['%s'] * len(item_dict))
        keys = ','.join(item_dict.keys())
        sql = 'INSERT INTO {table}({keys}) VALUES ({values})'.format(table=self.table, keys=keys, values=values)
        try:
            if cursor.execute(sql, tuple(item_dict.values())):  # 第一个值为sql语句第二个为 值 为一个元组
                print('数据入库成功!')
                self.client.commit()
        except Exception as e:
            print(e)

            print('数据已存在!')
            self.client.rollback()
        return item

    def close_spider(self, spider):

        self.client.close()
#定义下载
class MyFilePipeline(FilesPipeline):

    def get_media_requests(self, item, info):
        for file_url in item['file_urls']:
            yield scrapy.Request(file_url)

    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 file")
        item['file_urls'] = image_paths
        return item

setting.py

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

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

BOT_NAME = 'wenzhou_web'

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

# mysql配置参数
MYSQL_HOST = "192.168.113.129"
MYSQL_PORT = 3306
MYSQL_USER = "root"
MYSQL_PASSWORD = ""
MYSQL_DB = 'web_datas'
TABLE = "web_wenzhou"

# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'wenzhou_web (+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 https://doc.scrapy.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 https://doc.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'wenzhou_web.middlewares.WenzhouWebSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES = {
   'wenzhou_web.middlewares.WenzhouWebDownloaderMiddleware': 500,
}

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

# Configure item pipelines
# See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES = {
    'wenzhou_web.pipelines.WenzhouWebPipeline': 300,
    # 下载文件管道
    'scrapy.pipelines.MyFilePipeline': 1,
}

FILES_STORE = './download'

# Enable and configure the AutoThrottle extension (disabled by default)
# See https://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 https://doc.scrapy.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'