34.scrapy解决爬虫翻页问题

nbzj.py

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

import scrapy

import re

from nbzj_web.items import NbzjWebItem

class NbzjSpider(scrapy.Spider):

    name = 'nbzj'

    allowed_domains = ['www.nbzj.net']

    start_urls = ['http://www.nbzj.net/MaterialPriceList.aspx']

    custom_settings = {

        "DOWNLOAD_DELAY": 1,

        "ITEM_PIPELINES": {

            'nbzj_web.pipelines.MysqlPipeline': 300,

        },

        "DOWNLOADER_MIDDLEWARES": {

            'nbzj_web.middlewares.NbzjWebDownloaderMiddleware': 500,

        },

    }

    def parse(self, response):

        _response=response.text

        # print(_response)

        #获取翻页参数

        __VIEWSTATE=re.findall(r'id="__VIEWSTATE" value="(.*?)" />',_response)

        A=__VIEWSTATE[0]

        # print(A)

        __EVENTVALIDATION=re.findall(r'id="__EVENTVALIDATION" value="(.*?)" />',_response)

        B=__EVENTVALIDATION[0]

        # print(B)

        #页码

        page_num=re.findall(r'>下页</a><a title="转到第(.*?)页"',_response)

        # print(page_num[0])

        max_page=page_num[0]

        # print(max_page)

        content={

            '__VIEWSTATE':A,

            '__EVENTVALIDATION':B,

            'page_num':max_page,

        }

        # 获取标签列表

        tag_list=response.xpath("//div[@class='fcon']/table[@class='mytable']//tr/td").extract()

        # print(tag_list)

　　　　  #这里我直接取文本出现问题，我就直接拿标签数据等下面在做字符串的修改删除

        list=[]

        try:

            tag1=tag_list[:9]

            list.append(tag1)

            tag2=tag_list[9:18]

            list.append(tag2)

            tag3=tag_list[18:27]

            list.append(tag3)

            tag4=tag_list[27:36]

            list.append(tag4)

            tag5=tag_list[36:45]

            list.append(tag5)

            tag6=tag_list[45:54]

            list.append(tag6)

            tag7=tag_list[54:63]

            list.append(tag7)

            tag8=tag_list[63:72]

            list.append(tag8)

            tag9=tag_list[72:81]

            list.append(tag9)

            tag10=tag_list[81:90]

            list.append(tag10)

            tag11=tag_list[99:108]

            list.append(tag11)

            tag12=tag_list[108:117]

            list.append(tag12)

            tag13=tag_list[117:126]

            list.append(tag13)

            tag14=tag_list[126:135]

            list.append(tag14)

            tag15=tag_list[135:144]

            list.append(tag15)

            print(list)

            for tag in list:

                item=NbzjWebItem()

                # print(tag)

                #代码

                code=tag[0].replace('<td style="text-align: center">','').replace('</td>','')

                # print(code)

                item['code']=code

                #名称

                name=tag[1].replace('<td>','').replace('</td>','')

                # print(name)

                item['name']=name

                #地区

                district=tag[2].replace('<td style="text-align: center">','').replace('</td>','')

                # print(district)

                item['district']=district

                #型号规格

                _type=tag[3].replace('<td>','').replace('</td>','')

                # print(_type)

                item['_type']=_type

                #单位

                unit=tag[4].replace('<td style="text-align: center">','').replace('</td>','')

                # print(unit)

                item['unit']=unit

                #除税价

                except_tax_price = tag[5].replace('<td style="text-align: right">','').replace('</td>','')

                # print(except_tax_price)

                item['except_tax_price']=except_tax_price

                #含税价

                tax_price = tag[6].replace('<td style="text-align: right">','').replace('</td>','')

                # print(tax_price)

                item['tax_price']=tax_price

                #时间

                time=tag[7].replace('<td style="text-align: center">','').replace('</td>','')

                print(time)

                item['time']=time

                # print('-'*100)

                yield item

            # print('*'*100)

        except:

            pass

        yield scrapy.Request(url=response.url,callback=self.parse_detail,meta={"data": content})

    def parse_detail(self,response):

        for h in range(2008,2019):

            list=['','','','','','','','','','','','']

            for j in list:

                try:

                    max_page=response.meta['data']['page_num']

                    # print(max_page)

                    for i in range(2,int(max_page)):

                        data={

                        '__VIEWSTATE': '{}'.format(response.meta['data']['__VIEWSTATE']),

                        '__VIEWSTATEGENERATOR': 'E53A32FA',

                        '__EVENTTARGET': 'ctl00$ContentPlaceContent$Pager',

                        '__EVENTARGUMENT':'{}'.format(i),

                        '__EVENTVALIDATION': '{}'.format(response.meta['data']['__EVENTVALIDATION']),

                        'HeadSearchType': 'localsite',

                        'ctl00$ContentPlaceContent$txtnewCode':'',

                        'ctl00$ContentPlaceContent$txtMaterualName':'',

                        'ctl00$ContentPlaceContent$ddlArea':'',

                        'ctl00$ContentPlaceContent$txtPublishDate': '{} - 0{}'.format(h,j),

                        'ctl00$ContentPlaceContent$ddlCategoryOne':'',

                        'ctl00$ContentPlaceContent$hidCateId':'',

                        'ctl00$ContentPlaceContent$txtSpecification':'',

                        'ctl00$ContentPlaceContent$Pager_input': '{}'.format(i-1),

                        'ctl00$foot$ddlsnzjw': '',

                        'ctl00$foot$ddlswzjw': '',

                        'ctl00$foot$ddlqtxgw': ''

                        }

                        yield scrapy.FormRequest(url=response.url, callback=self.parse, formdata=data, method="POST", dont_filter=False)

                except:

                    pass

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 NbzjWebItem(scrapy.Item):

    # define the fields for your item here like:

    # name = scrapy.Field()

    code=scrapy.Field()

    name=scrapy.Field()

    district=scrapy.Field()

    _type=scrapy.Field()

    unit=scrapy.Field()

    except_tax_price=scrapy.Field()

    tax_price =scrapy.Field()

    time=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 NbzjWebSpiderMiddleware(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 NbzjWebDownloaderMiddleware(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

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

from scrapy.conf import settings

import pymysql

class NbzjWebPipeline(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()

setting.py

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

# Scrapy settings for nbzj_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 = 'nbzj_web'

SPIDER_MODULES = ['nbzj_web.spiders']

NEWSPIDER_MODULE = 'nbzj_web.spiders'

# mysql配置参数

MYSQL_HOST = "172.16.10.197"

MYSQL_PORT = 3306

MYSQL_USER = "root"

MYSQL_PASSWORD = ""

MYSQL_DB = 'web_datas'

TABLE = "web_nbzj"

# Crawl responsibly by identifying yourself (and your website) on the user-agent

#USER_AGENT = 'nbzj_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 = {

#    'nbzj_web.middlewares.NbzjWebSpiderMiddleware': 543,

#}

# Enable or disable downloader middlewares

# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html

DOWNLOADER_MIDDLEWARES = {

   'nbzj_web.middlewares.NbzjWebDownloaderMiddleware': 543,

}

# 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 = {

   'nbzj_web.pipelines.NbzjWebPipeline': 300,

}

# 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'