Python3[爬虫实战] 爬虫之scrapy爬取爱上程序网存MongoDB（android模块）

爱上程序网

（http://www.aichengxu.com/android）

缘由：这个网站是在工作中谷歌找问题找出来的，然后发现里面的文章挺多的， 毕竟自己平时比较喜欢看技术文章，什么都想懂，什么都懂得不深入，这不，想要转爬虫工作的，现在还在继续android开发中。。

废话不多说。

来个数据库的结果：

这里写图片描述

---

为什么暂时是这些呢？因为用的循环用了10000次，可能还会多，数据爬取到了2013年了，想必这个网站确实是建站比较久了，可能遍历的话还会有更多吧。在第二次爬取数据的时候一共爬取了24万左右的数据，可能还有多吧。

这里总结一下经验：
之前在pycharm中直接在文件夹中进行写scrapy工程导入模块一直出错，原因是导入不进去。可以看以下截图对比：

这里写图片描述

可以看出来下面那个项目在工程中没有变黑，所以在spider中导入items里面的类，是一直导入报错的，说是no module named ‘’xxx‘’

解决方法：

需要我们在file菜单栏中重新open。。然后导入该项目，再关联到该工程中，add xxx的 然后项目就变成黑色了， 这样子导包就正常了。

抓取的数据主要是：

阅读量，标题，标题链接（内容详情页），内容，时间

---

这里写图片描述

使用scrapy 进行数据的爬取，在parse（）方法中用的还不是很熟练，一边调，一边用把。

步骤一：

settings文件的配置：

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

# Scrapy settings for aichengxu 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 = 'aichengxu'

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

# Crawl responsibly by identifying yourself (and your website) on the user-agent
# USER_AGENT = 'aichengxu (+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,image/webp,*/*;q=0.8',
    'Accept-Language': 'zh-CN,zh;q=0.8',
    'Cache-Control': 'max-age=0',
    'Connection': 'keep-alive',
    'Cookie': 'ras=24656333; cids_AC31=24656333',
    'Host': 'www.aichengxu.com',
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.75 Safari/537.36',
}

# 配置mongoDB
MONGO_HOST = "127.0.0.1"  # 主机IP
MONGO_PORT = 27017  # 端口号
MONGO_DB = "aichengxu2"  # 库名
MONGO_COLL = "ai_chengxu"  # collection

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

# Enable or disable downloader middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
# DOWNLOADER_MIDDLEWARES = {
#    'aichengxu.middlewares.MyCustomDownloaderMiddleware': 543,
#     'aichengxu.middlewares.MyCustomDownloaderMiddleware': 543,
#     'aichengxu.middlewares.MyCustomDownloaderMiddleware': 543,
# }

# 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 = {
    'aichengxu.pipelines.AichengxuPipeline': 300,
    'aichengxu.pipelines.DuoDuoMongo': 300,
    'aichengxu.pipelines.JsonWritePipline': 300,
}

# 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'

当然有用的也就那几个没有注释掉的，这是一种习惯吧，不然后面有时候都在想为什么scrapy没有跑起来，或者直接报错，呵呵。

步骤二：

进行items里面的定义：

# -*- 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 AichengxuItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    pass

class androidItem(scrapy.Item):
    # 阅读量
    count = scrapy.Field()
    # 标题
    title = scrapy.Field()
    # 链接
    titleLink = scrapy.Field()
    # 描述
    desc = scrapy.Field()
    # 时间
    time = scrapy.Field()

步骤三：

spiders里面的代码编写

# -*- coding: utf-8 -*-
# @Time    : 2017/8/25 21:54
# @Author  : 蛇崽
# @Email   : [email protected]
# @File    : aichengxuspider.py 爱程序网 www.aichengxu.com

import scrapy
from aichengxu.items import androidItem
import logging
class aiChengxu(scrapy.Spider):

    name = 'aichengxu'

    allowed_domains = ['www.aichengxu.com']

    start_urls = ["http://www.aichengxu.com/android/{}/".format(n) for n in range(1,10000)]

    def parse(self, response):
        node_list = response.xpath("//*[@class='item-box']")
        print('nodelist',node_list)
        for node in node_list:
            android_item = androidItem()
            count = node.xpath("./div[@class='views']/text()").extract()
            title_link = node.xpath("./div[@class='bd']/h3/a/@href").extract()
            title = node.xpath("./div[@class='bd']/h3/a/text()").extract()
            desc = node.xpath("./div[@class='bd']/div[@class='desc']/text()").extract()
            time = node.xpath("./div[@class='bd']/div[@class='item-source']/span[2]").extract()
            print(count,title,title_link,desc,time)
            android_item['title'] = title
            android_item['titleLink'] = title_link
            android_item['desc'] = desc
            android_item['count'] = count
            android_item['time'] = time
            yield android_item

这里对yield这个关键字说一下自己的看法：就是返回该条目，并继续执行下一个任务，或者说，把item返回去，然后继续下一条爬虫吧。

步骤四：

piplines代码：

# -*- 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
import json

import pymongo
from scrapy.conf import settings

class AichengxuPipeline(object):
    def process_item(self, item, spider):
        return item
class DuoDuoMongo(object):
    def __init__(self):
        self.client = pymongo.MongoClient(host=settings['MONGO_HOST'], port=settings['MONGO_PORT'])
        self.db = self.client[settings['MONGO_DB']]
        self.post = self.db[settings['MONGO_COLL']]

    def process_item(self, item, spider):
        postItem = dict(item)
        self.post.insert(postItem)
        return item

# 写入json文件
class JsonWritePipline(object):
    def __init__(self):
        self.file = open('爱上程序网2.json','w',encoding='utf-8')

    def process_item(self,item,spider):
        line  = json.dumps(dict(item),ensure_ascii=False)+"\n"
        self.file.write(line)
        return item

    def spider_closed(self,spider):
        self.file.close()

这里主要写了两种类型的存储，一个是mogodb，一个是json文件的存储

这样，代码就爬完了，然后就这样子结束了，代码久了不写，生疏了许多。

有一个疑问：这里爬取了24万的数据，没有在中途因为cookie或者代理的原因被静止，可能在settings里面设置了请求头的缘故吧，DEFAULT_REQUEST_HEADERS

再说一下这个网站为什么自己为什么想爬，总感觉自己对技术驱动性很强吧，当然啦，android并不是我最喜欢的吧，可能或者有些畏惧它，android适配很恶心的。机型，屏幕什么的。

这个网站还有很多其他条目：

这里写图片描述

如果全部爬取下来，老实说，我没有进行爬取过，有想法的小伙伴可是试一试，最后把代码上传到我的github上：

我的github