爬虫—爬取微博热搜榜

1. 引言

利用scrapy框架爬取微博热搜榜网站前50条热搜。

爬取信息：热搜排名、热搜新闻名、热搜新闻热搜量。

数据存储：存储为.csv文件。

2.爬取流程

• 新建scrapy爬虫项目：
  在终端输入以下代码，创建一个基于scrapy框架的爬虫项目，该项目为：weiboreshou。

scrapy startproject weiboreshou

• 在weiboreshou项目下新建爬虫程序文件
  在终端输入以下代码，创建一个名为reshou的爬虫程序文件。

cd weigoreshou
scrapy genspider reshou s.weibo.com

新建的项目包含以下文件：

• 编写items.py文件，定义需要获取的信息字段。

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

import scrapy


class WeiboreshouItem(scrapy.Item):
    order = scrapy.Field() #热搜排名
    news = scrapy.Field() #热搜新闻
    number = scrapy.Field() #热搜量
    # define the fields for your item here like:
    # name = scrapy.Field()
    #pass

• 编写settings.py程序，进行项目的一些设置

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

BOT_NAME = 'weiboreshou'

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


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

# Obey robots.txt rules
ROBOTSTXT_OBEY = False #设置为不遵守ROBOTSTXT协议

# 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://docs.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
DOWNLOAD_DELAY = 3 #设置下载延迟时间为3秒
# 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',
  'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.73'
}

# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
     
#    'weiboreshou.middlewares.WeiboreshouSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
     
#    'weiboreshou.middlewares.WeiboreshouDownloaderMiddleware': 543,
#}

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

# Configure item pipelines
# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html
#ITEM_PIPELINES = {
     
#    'weiboreshou.pipelines.WeiboreshouPipeline': 300,
#}

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

• 编写reshou.py文件，爬取网站信息
  利用CSS选择器定位所需信息的位置，解析HTML源码。
  

import scrapy
from ..items import WeiboreshouItem

class ReshouSpider(scrapy.Spider):
    name = 'reshou'
    allowed_domains = ['s.weibo.com']
    start_urls = ['https://s.weibo.com/top/summary']

    def parse(self, response):
        
        list_selector = response.css('tbody tr')
        
        for one_selector in list_selector:
            
            order = one_selector.css(' td.ranktop::text').extract()
            news = one_selector.css(' a::text').extract()
            number = one_selector.css(' span::text').extract()
            
            item = WeiboreshouItem()
            
            item['order'] = order
            item['news'] = news
            item['number'] = number
            
            yield item
        #pass

• 在终端输入以下程序，进行数据爬取

scrapy crawl reshou -o reshou.csv

3.查看输出数据

写在最后

关于scrapy框架，大家可以参考以下文章：

功能强大的python包（八）：Scrapy （网络爬虫框架）

该项目的环境配置可以参考以下文章：

开发环境配置