作用

在Scrapy框架中，settings.py 文件起着非常重要的作用，它用于配置和控制整个Scrapy爬虫项目的行为、性能和功能。

setting.py文件的介绍

# Scrapy settings for haodaifu 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# 设置爬虫的名称
BOT_NAME = "spidername"# 指定包含的爬虫代码的模块
SPIDER_MODULES = ["spidername.spiders"]
NEWSPIDER_MODULE = "spidername.spiders"# 设置用户代理，用于模拟浏览器或特定的爬虫身份
# 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/91.0.4472.124 Safari/537.36"# 配置爬虫是否遵循robots.txt柜子
# Obey robots.txt rules
ROBOTSTXT_OBEY = False# 控制并发请求的数量（默认为16）
# Configure maximum concurrent requests performed by Scrapy (default: 16)
CONCURRENT_REQUESTS = 64# 设置下载延迟，控制请求之间的时间间隔，以避免对目标服务器造成过大负载
# 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# 配置每个域名的最大并发请求数
# The download delay setting will honor only one of:
CONCURRENT_REQUESTS_PER_DOMAIN = 16# 设置每个IP地址的最大并发请求数
CONCURRENT_REQUESTS_PER_IP = 16# 启用或禁用cookies
# Disable cookies (enabled by default)
COOKIES_ENABLED = False# 启用或禁用Telnet控制台
# Disable Telnet Console (enabled by default)
TELNETCONSOLE_ENABLED = False# 默认的请求头
# Override the default request headers:
DEFAULT_REQUEST_HEADERS = {'Referer': 'https://www.xxx.com/','User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36',
}# 启用或禁用爬虫中间件
# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
# 爬虫中间件及其顺序
SPIDER_MIDDLEWARES = {"spidername.middlewares.SpidernameSpiderMiddleware": 543,
}# 启用或禁用下载中间件
# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
# 下载中间件及其顺序
DOWNLOADER_MIDDLEWARES = {"spidername.middlewares.SpidernameDownloaderMiddleware": 543,
}# 启用和配置scrapy扩展
# Enable or disable extensions
# See https://docs.scrapy.org/en/latest/topics/extensions.html
EXTENSIONS = {"scrapy.extensions.telnet.TelnetConsole": None,
}# 启用或禁用项目管道
# Configure item pipelines
# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html
# 项目管道
ITEM_PIPELINES = {"spidername.pipelines.spidernamePipeline": 300,
}# Enable and configure the AutoThrottle extension (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/autothrottle.html
# 是否启用自动限速
AUTOTHROTTLE_ENABLED = True# 初始化下载延迟（秒） 
# The initial download delay
AUTOTHROTTLE_START_DELAY = 5# 最大下载延迟（秒）
# 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
# scrapy 的目标并发请求数
AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0# Enable showing throttling stats for every response received:
# 是否启用自动限速调试模式
AUTOTHROTTLE_DEBUG = False# 启用和配置http缓存
# Enable and configure HTTP caching (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
# 是否启用HTTP缓存
HTTPCACHE_ENABLED = True# 缓存超时时间（秒）
HTTPCACHE_EXPIRATION_SECS = 0# 缓存目录
HTTPCACHE_DIR = "httpcache"# 忽略缓存的HTTP状态码列表
HTTPCACHE_IGNORE_HTTP_CODES = []HTTPCACHE_STORAGE = "scrapy.extensions.httpcache.FilesystemCacheStorage"# Set settings whose default value is deprecated to a future-proof value
REQUEST_FINGERPRINTER_IMPLEMENTATION = "2.7"
TWISTED_REACTOR = "twisted.internet.asyncioreactor.AsyncioSelectorReactor"# 输出feed的编码
FEED_EXPORT_ENCODING = "utf-8"