Scrapy笔记

基本使用流程

使用爬取豆瓣电影 Top 250 (douban.com)作为案例

创建项目

scrapy startproject douban_movie

这行命令会在当前文件夹下创建名称为douban_movie的爬虫项目

创建爬虫

scrapy genspider douban movie.douban.com

创建项目后，进入项目文件夹，再执行当前命令会在spider_douban/spiders文件夹下创建一个douban.py爬虫文件

定义数据结构

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

import scrapy


class SpiderDoubanItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    movie_name = scrapy.Field()  # 电影名称
    movie_score = scrapy.Field()  # 电影评分

在items文件中，新建SpiderDoubanItem类，定义要爬取的字段

编写爬虫逻辑

import scrapy

from spider_douban.items import SpiderDoubanItem


class DoubanSpider(scrapy.Spider):
    name = "douban"
    allowed_domains = ["movie.douban.com"]
    start_urls = ["https://movie.douban.com/top250"]

    def parse(self, response):
        if response.status == 403:
            self.logger.error('访问被拒绝，请检查反爬虫设置')
            return
        
        movies = response.css(".item")
        for movie in movies:
            item = SpiderDoubanItem()
            item["movie_name"] = movie.css(".title::text").get()
            item["movie_score"] = movie.css(".rating_num::text").get()
            yield item

        next_page = response.css(".next a::attr(href)").get()
        if next_page is not None:
            yield response.follow(next_page, self.parse)

修改配置

# Scrapy settings for spider_douban 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 = "spider_douban"

SPIDER_MODULES = ["spider_douban.spiders"]
NEWSPIDER_MODULE = "spider_douban.spiders"


# Crawl responsibly by identifying yourself (and your website) on the user-agent
USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36'

# 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://docs.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
DOWNLOAD_DELAY = 2  # 延迟2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 = True

# 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://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    "spider_douban.middlewares.SpiderDoubanSpiderMiddleware": 543,
#}

# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
#    "spider_douban.middlewares.SpiderDoubanDownloaderMiddleware": 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 = {
    'spider_douban.pipelines.SpiderDoubanPipeline': 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"

# Set settings whose default value is deprecated to a future-proof value
TWISTED_REACTOR = "twisted.internet.asyncioreactor.AsyncioSelectorReactor"
FEED_EXPORT_ENCODING = "utf-8"

# 配置输出格式
FEED_FORMAT = 'json'
FEED_URI = 'output.json'

主要配置：

1. USER_AGENT
1. ITEM_PIPELINES，数据管道
1. FEED_FORMAT、FEED_URI，输出格式

使用进阶

中间件

爬虫中间件，主要用来处理数据的输入输出；

下载中间件，主要用来出来数据的下载

管道

主要处理数据的保存