Scrapy框架的学习(8.scrapy中settings.py里面配置说明以及怎样设置配置或者参数以及怎样使用)

1.settings.py里面的参数说明

    每个参数其对应的官方得文档的网址

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

# Scrapy settings for tencent 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 = 'tencent'

SPIDER_MODULES = ['tencent.spiders']
#  新建一个爬虫会在什么位置
NEWSPIDER_MODULE = 'tencent.spiders'

# LOG_LEVEL = "WARNING"

# Crawl responsibly by identifying yourself (and your website) on the user-agent
# 浏览器的标识
# USER_AGENT = 'tencent (+http://www.yourdomain.com)'

# Obey robots.txt rules
# 是否遵守robots协议
ROBOTSTXT_OBEY = True

# Configure maximum concurrent requests performed by Scrapy (default: 16)
# 设置最大并发请求
#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
# 下载延迟
#DOWNLOAD_DELAY = 3
# The download delay setting will honor only one of:
# 每个域名的最大并发请求数
#CONCURRENT_REQUESTS_PER_DOMAIN = 16
# 每个IP的最大并发请求数
#CONCURRENT_REQUESTS_PER_IP = 16

# Disable cookies (enabled by default)
# cookies 是否开启，默认是被开启来的
#COOKIES_ENABLED = False

# Disable Telnet Console (enabled by default)
# Telnet 插件是否开启
#TELNETCONSOLE_ENABLED = False

# Override the default request headers:
# 默认请求头
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
# 爬虫中间键
#SPIDER_MIDDLEWARES = {
#    'tencent.middlewares.TencentSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
# 下载中间键
#DOWNLOADER_MIDDLEWARES = {
#    'tencent.middlewares.TencentDownloaderMiddleware': 543,
#}

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

# Configure item pipelines
# See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
# 设置 pipelines
ITEM_PIPELINES = {
   'tencent.pipelines.TencentPipeline': 300,
}

# Enable and configure the AutoThrottle extension (disabled by default)
# See https://doc.scrapy.org/en/latest/topics/autothrottle.html
# 通过设置下面的参数可以让爬虫的速度变慢一点
#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)
# 有关HTTP缓存设置
# 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'

2. 在settings.py里面定义好的配置或者参数怎样在爬虫和pipelines等里面用呢？

    (1)    在其他py文件通过  from ...  import ... 的方式直接导入就行

          想在那个文件用，直接导入直接用就行

    (2) 可以使用   .settings 的方式， 因为是一个字典，

          可以通过   .settings["配置或参数名"]  或者   .settings.get("配置或参数名"）

         例如在爬虫文件里的parese(self,response) 里面进行    

             self.settings["配置或参数名"]   或者   self.settings.get("配置或参数名")

        在pipelines里面 def process_item(self, item, spider) 的方法里面，

         spider.settings["配置或参数名"]   或者   spider.settings.get("配置或参数名")