Python Scrapy爬虫框架学习笔记（一）

野性酷女 2022-04-12 11:30 374阅读 0赞

最近学完Python之后感觉要学明白一门编程语言就需要不停用，因此就选择了相对难度小的爬虫练习，话不多说，看笔记：

# **运行环境：** #

OS：Win10  
Python：3.6  
Scrapy：1.5.1  
IDE：Pycharm

# **工程代码：** #

目前主要做了一个爬取豆瓣前250电影的小爬虫，代码也是按照Scrapy的手册上学到的现学现用，还望各位大神赐教。

### 1，setting.py文件 ###

# -*- coding: utf-8 -*-
    import time
    
    # Scrapy settings for scrawlDianpingData 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 = 'scrawlDianpingData'
    
    SPIDER_MODULES = ['scrawlDianpingData.spiders']
    NEWSPIDER_MODULE = 'scrawlDianpingData.spiders'
    
    
    # Crawl responsibly by identifying yourself (and your website) on the user-agent
    RANDOM_UA_TYPE = 'random'
    
    DOWNLOADER_MIDDLEWARES = {
        'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': None,
        'scrapy_fake_useragent.middleware.RandomUserAgentMiddleware': 400,
    }
    
    # Obey robots.txt rules
    ROBOTSTXT_OBEY = True
    
    # 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 = {
       'scrawlDianpingData.middlewares.ScrawldianpingdataSpiderMiddleware': 543,
    }
    
    # Enable or disable downloader middlewares
    # See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
    # DOWNLOADER_MIDDLEWARES = {
    #    'scrawlDianpingData.middlewares.ScrawldianpingdataDownloaderMiddleware': 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 = {
    #    'scrawlDianpingData.pipelines.ScrawldianpingdataPipeline': 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'
    HTTPERROR_ALLOWED_CODES = [403]
    
    #Export report
    FEED_FORMAT = "csv"
    FEED_EXPORT_ENCODING = 'utf-8-sig'
    FEED_URI = "file:///C:/Spider_Output/%s.csv" % ("report_"+time.strftime("%Y%m%d%H%M%S", time.localtime()))

## ,2，主程序crawlmovie.py文件 ##

import scrapy
    import os
    
    
    class CrawlMovie(scrapy.Spider):
        name = "movie"
    
        start_urls = [
            'https://movie.douban.com/top250',
        ]
    
        def parse(self, response):
               for item in response.css('div.item'):
                   yield{
                       '排名': item.css('div.pic em::text').extract_first().strip(),
                       '电影名': item.css('span.title::text').extract_first().strip(),
                       '链接': item.css('div.hd a::attr(href)').extract_first().strip(),
                       '详细': item.css('div.bd p::text').extract_first().strip(),
                       '评分': item.css('span.rating_num::text').extract_first().strip(),
                       '评分人数': item.css('div.star span:nth-child(4)::text').extract_first().strip(),
                       '格言': item.css('span.inq::text').extract_first(),
                   }
    
               next_page = response.css('span.next a::attr(href)').extract_first()
               if next_page is not None:
                   yield response.follow(next_page, self.parse)
    
               #delete empty files
               path = 'C:/Spider_Output/'
               for file in os.listdir(path):
                   if os.stat(path+file).st_size == 0:
                       try:
                           os.remove(path+file)
                           self.log('delete %s success!!!' % file)
                       except OSError as oe:
                           print("file is using.")

### 3，程序启动入口，主要用在配置 ###

from scrapy import cmdline
    
    
    cmdline.execute("scrapy crawl movie".split())

# 练习中遇到的问题： #

1，编码问题，如果爬去的内容有中文汉字，在setting.py中加入下边代码

FEED_EXPORT_ENCODING = 'utf-8-sig'

其他的解决方案都试过了，但是就这个好用

2，从网页上爬去的时候会出现无值的情况，所以每个爬取之后及得用上extract\_first()这个方法，并且后边记得别用strip()

去首位空格

3，如果一些网站禁掉爬虫，记得加上fake-useragent这个package  
  
最后把结果也分享了

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2dpdGh1Yl8zNjg0OTc3Mw_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2dpdGh1Yl8zNjg0OTc3Mw_size_16_color_FFFFFF_t_70]: /images/20220412/02e22b36beed40bf9cfc33498fd48674.png