scrapy爬虫项目的创建基本设置

一、 创建指令

$: scrapy startproject 项目名
# 例如
$: scrapy startproject MySpider

• cd 项目名

进入爬虫项目的目录
生成爬虫文件（模板）

$: scrapy genspider 爬虫名字 爬虫的网址
# 例如
$: scrapy genspider test baidu.com

二、 setting文件的设置

# 这里是是否准守爬虫规则， 默认是True， 将这里改成False
# Obey robots.txt rules
ROBOTSTXT_OBEY = True

# 设置控制台日志的显示，等级低于warning的日志信息，就不会显示出来
LOG_LEVEL = 'WARNING'

# headers取消注释， 还有UA标识
DEFAULT_REQUEST_HEADERS = {
   'Accept': 	'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
   'Accept-Language': 'en',
}

USER_AGENT = 'maoyan (+http://www.yourdomain.com)'
# 将其中的内容换成浏览器标识

下面是爬取并下载一个网站的高清壁纸的setting文件

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

# Scrapy settings for wallpaper 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 = 'wallpaper'

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

LOG_LEVEL = "WARNING"

# Crawl responsibly by identifying yourself (and your website) on the user-agent
USER_AGENT = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 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://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 = {
#    'wallpaper.middlewares.WallpaperSpiderMiddleware': 543,
# }

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
# DOWNLOADER_MIDDLEWARES = {
#    'wallpaper.middlewares.WallpaperDownloaderMiddleware': 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 = {
    'scrapy.pipelines.images.ImagesPipeline': 1,
    # 'scrapy.pipelines.files.FilesPipeline': 2,
    'wallpaper.pipelines.WallpaperPipeline': 300,

}
# 设置下载参数
# FILES_STORE = "D:"  # 文件的存储路径
IMAGES_STORE = "D:/images"  # 图片的存储路径
# 避免下载最近90天已经下载过的文件内容
FILES_EXPIRES = 90
# 避免下载最近90天已经下载过的图像内容
IMAGES_EXPIRES = 0
# 设置图片缩略图
IMAGES_THUMBS = {
    'small': (50, 50),
    'big': (250, 250)
}
#该字段的值为xxxItem中定义的存储图片链接的img_urls字段
IMAGES_URLS_FIELD = "img_urls"
# 该字段的值为xxxItem中定义的存储图片信息的imgages字段
IMAGES_RESULT_FIELD = "images"

# 图片过滤器，最小高度和宽度，低于此尺寸不下载
IMAGES_MIN_HEIGHT = 110
IMAGES_MIN_WIDTH = 110

# 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'