setting 经常使用配置

一，保存logging 信息

# 保存log信息的文件名
LOG_LEVEL = "INFO"
LOG_STDOUT = True
LOG_ENCODING = 'utf-8'
# 路径  os.path.dirname(os.path.dirname(os.path.dirname(__file__)))
LOG_FILE = os.path.dirname(__file__) + "/SHANGSHIYAOPINGMULU_error.log"

二，禁止重定向

REDIRECT_ENABLED = False

三，设置延时

import random
DOWNLOAD_DELAY = random.random() + random.random()
RANDOMIZE_DOWNLOAD_DELAY = True

四，设置USER_AGENT

USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko'

五，启动spider下面的所有爬虫

1.与spider同级目录中建立commands文件夹

mkdir commands

2.进入commands文件夹

cd commands

3.建立__init__.py文件

touch __init__.py

4.建立crawlall.py文件

touch crawlall.py

5.打开crawlall文件编写代码

vim crawlall.py

from scrapy.commands import ScrapyCommand
from scrapy.crawler import CrawlerRunner
from scrapy.exceptions import UsageError
from scrapy.utils.conf import arglist_to_dict


class Command(ScrapyCommand):
    requires_project = True

    def syntax(self):
        return '[options]'

    def short_desc(self):
        return 'Runs all of the spiders'

    def add_options(self, parser):
        ScrapyCommand.add_options(self, parser)
        parser.add_option("-a", dest="spargs", action="append", default=[], metavar="NAME=VALUE",
                          help="set spider argument (may be repeated)")
        parser.add_option("-o", "--output", metavar="FILE",
                          help="dump scraped items into FILE (use - for stdout)")
        parser.add_option("-t", "--output-format", metavar="FORMAT",
                          help="format to use for dumping items with -o")

    def process_options(self, args, opts):
        ScrapyCommand.process_options(self, args, opts)
        try:
            opts.spargs = arglist_to_dict(opts.spargs)
        except ValueError:
            raise UsageError("Invalid -a value, use -a NAME=VALUE", print_help=False)

    def run(self, args, opts):
        # settings = get_project_settings()

        spider_loader = self.crawler_process.spider_loader
        for spidername in args or spider_loader.list():
            print("*********cralall NewsSpider************")
            self.crawler_process.crawl(spidername, **opts.spargs)
        self.crawler_process.start()

6.配置commands

COMMANDS_MODULE = 'spider.commands'

六，设置从新发请求的状态码

RETRY_HTTP_CODES = [500, 520]

七，配置redis

# reids链接信息
REDIS_HOST = "192.168.1.235"
REDIS_PORT = 6379
REDIS_PARAMS = {
    "password": "KangCe@0608",
}

# 1(必须). 使用了scrapy_redis的去重组件，在redis数据库里作去重
DUPEFILTER_CLASS = "scrapy_redis.dupefilter.RFPDupeFilter"

# 2(必须). 使用了scrapy_redis的调度器，在redis里分配请求
SCHEDULER = "scrapy_redis.scheduler.Scheduler"

# 3(必须). 在redis中保持scrapy-redis用到的各个队列，从而容许暂停和暂停后恢复，也就是不清理redis queues
SCHEDULER_PERSIST = True

# 4(必须). 经过配置RedisPipeline将item写入key为 spider.name : items 的redis的list中，供后面的分布式处理item
# 这个已经由 scrapy-redis 实现，不须要咱们写代码，直接使用便可
ITEM_PIPELINES = {
    # 'AQI.pipelines.AqiJsonPipeline': 200,
    # 'AQI.pipelines.AqiCSVPipeline': 300,
    # 'AQI.pipelines.AqiRedisPipeline': 400,
    # 'AQI.pipelines.AqiMongoPipeline': 500,
    'scrapy_redis.pipelines.RedisPipeline': 100
}

 八.settings.py配置文件详解

# Scrapy项目的名字,这将用来构造默认 User-Agent,同时也用来log,当您使用 startproject 命令建立项目时其也被自动赋值。
BOT_NAME = 'demo1'

# Scrapy搜索spider的模块列表 默认: [xxx.spiders]
SPIDER_MODULES = ['demo1.spiders']
# 使用 genspider 命令建立新spider的模块。默认: 'xxx.spiders'
NEWSPIDER_MODULE = 'demo1.spiders'

# 爬取的默认User-Agent，除非被覆盖
USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36'

# 保存log信息的文件名
LOG_LEVEL = "INFO"
LOG_STDOUT = True
LOG_ENCODING = 'utf-8'
# 路径  os.path.dirname(os.path.dirname(os.path.dirname(__file__)))
LOG_FILE = "SHANGSHIYAOPINGMULU_error.log"

# 禁止重镜像
REDIRECT_ENABLED = False



# 设置延时
import random
DOWNLOAD_DELAY = random.random() + random.random()
RANDOMIZE_DOWNLOAD_DELAY = True

# 若是启用,Scrapy将会采用 robots.txt策略
ROBOTSTXT_OBEY = True

# 设置从新发请求的状态码
RETRY_HTTP_CODES = [500, 520]

# Scrapy downloader 并发请求(concurrent requests)的最大值,默认: 16
CONCURRENT_REQUESTS = 32

# 爬虫容许的最大深度，能够经过meta查看当前深度；0表示无深度
DEPTH_LIMIT = 3

#  爬取时，0表示深度优先Lifo(默认)；1表示广度优先FiFo
# 后进先出，深度优先
DEPTH_PRIORITY = 0
SCHEDULER_DISK_QUEUE = 'scrapy.squeue.PickleLifoDiskQueue'
SCHEDULER_MEMORY_QUEUE = 'scrapy.squeue.LifoMemoryQueue'
# 先进先出，广度优先
DEPTH_PRIORITY = 1
SCHEDULER_DISK_QUEUE = 'scrapy.squeue.PickleFifoDiskQueue'
SCHEDULER_MEMORY_QUEUE = 'scrapy.squeue.FifoMemoryQueue'

# 调度器队列
from scrapy.core.scheduler import Scheduler
SCHEDULER = 'scrapy.core.scheduler.Scheduler'

# 访问URL去重
# DUPEFILTER_CLASS = 'step8_king.duplication.RepeatUrl'

# 为同一网站的请求配置延迟（默认值：0）
# See http://scrapy.readthedocs.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
# 下载器在下载同一个网站下一个页面前须要等待的时间,该选项能够用来限制爬取速度,减轻服务器压力。同时也支持小数:0.25 以秒为单位
DOWNLOAD_DELAY = 3

# 下载延迟设置只有一个有效
# 对单个网站进行并发请求的最大值。
CONCURRENT_REQUESTS_PER_DOMAIN = 16
# 对单个IP进行并发请求的最大值。若是非0,则忽略 CONCURRENT_REQUESTS_PER_DOMAIN 设定,使用该设定。 也就是说,并发限制将针对IP,而不是网站。该设定也影响 DOWNLOAD_DELAY: 若是 CONCURRENT_REQUESTS_PER_IP 非0,下载延迟应用在IP而不是网站上。
CONCURRENT_REQUESTS_PER_IP = 16

# 禁用Cookie（默认状况下启用）
COOKIES_ENABLED = False

# 禁用Telnet控制台（默认启用）
TELNETCONSOLE_ENABLED = False

# 覆盖默认请求标头：
DEFAULT_REQUEST_HEADERS = {
  'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
  'Accept-Language': 'en',
}

# 启用或禁用蜘蛛中间件
# See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
SPIDER_MIDDLEWARES = {
   'demo1.middlewares.Demo1SpiderMiddleware': 543,
}

# 启用或禁用下载器中间件
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES = {
   'demo1.middlewares.MyCustomDownloaderMiddleware': 543,
}

# 启用或禁用扩展程序
# See http://scrapy.readthedocs.org/en/latest/topics/extensions.html
EXTENSIONS = {
   'scrapy.extensions.telnet.TelnetConsole': None,
}

# 配置项目管道
# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES = {
   'demo1.pipelines.Demo1Pipeline': 300,
}

# 启用和配置AutoThrottle扩展（默认状况下禁用）(开始自动限速)
# See http://doc.scrapy.org/en/latest/topics/autothrottle.html
AUTOTHROTTLE_ENABLED = True

# 初始下载延迟
AUTOTHROTTLE_START_DELAY = 5

# 最大下载延迟
AUTOTHROTTLE_MAX_DELAY = 10

# 禁止重试
RETRY_ENABLED = False

# 下载超时
DOWNLOAD_TIMEOUT = 10

# 下载重试次数
RETRY_ITEMS=5

# 在高延迟的状况下设置的最大下载延迟
AUTOTHROTTLE_MAX_DELAY = 60


# Scrapy请求的平均数量应该并行发送每一个远程服务器( 平均每秒并发数)
AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0

# 启用显示所收到的每一个响应的调节统计信息：
AUTOTHROTTLE_DEBUG = False

# 启用和配置HTTP缓存（默认状况下禁用）
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
# # 是否启用缓存策略
HTTPCACHE_ENABLED = True
# 缓存策略：全部请求均缓存，下次在请求直接访问原来的缓存便可
HTTPCACHE_POLICY = "scrapy.extensions.httpcache.DummyPolicy"
# 缓存策略：根据Http响应头：Cache-Control、Last-Modified 等进行缓存的策略
HTTPCACHE_POLICY = "scrapy.extensions.httpcache.RFC2616Policy"
# 缓存超时时间
HTTPCACHE_EXPIRATION_SECS = 0
# 缓存保存路径
HTTPCACHE_DIR = 'httpcache'
# 缓存忽略的Http状态码
HTTPCACHE_IGNORE_HTTP_CODES = []
# 缓存存储的插件
HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'


"""
19. 代理，须要在环境变量中设置
    from scrapy.contrib.downloadermiddleware.httpproxy import HttpProxyMiddleware

    方式一：使用默认
        os.environ
        {
            http_proxy:http://root:woshiniba@192.168.11.11:9999/
            https_proxy:http://192.168.11.11:9999/
        }
    方式二：使用自定义下载中间件

    def to_bytes(text, encoding=None, errors='strict'):
        if isinstance(text, bytes):
            return text
        if not isinstance(text, six.string_types):
            raise TypeError('to_bytes must receive a unicode, str or bytes '
                            'object, got %s' % type(text).__name__)
        if encoding is None:
            encoding = 'utf-8'
        return text.encode(encoding, errors)

    class ProxyMiddleware(object):
        def process_request(self, request, spider):
            PROXIES = [
                {'ip_port': '111.11.228.75:80', 'user_pass': ''},
                {'ip_port': '120.198.243.22:80', 'user_pass': ''},
                {'ip_port': '111.8.60.9:8123', 'user_pass': ''},
                {'ip_port': '101.71.27.120:80', 'user_pass': ''},
                {'ip_port': '122.96.59.104:80', 'user_pass': ''},
                {'ip_port': '122.224.249.122:8088', 'user_pass': ''},
            ]
            proxy = random.choice(PROXIES)
            if proxy['user_pass'] is not None:
                request.meta['proxy'] = to_bytes（"http://%s" % proxy['ip_port']）
                encoded_user_pass = base64.encodestring(to_bytes(proxy['user_pass']))
                request.headers['Proxy-Authorization'] = to_bytes('Basic ' + encoded_user_pass)
                print "**************ProxyMiddleware have pass************" + proxy['ip_port']
            else:
                print "**************ProxyMiddleware no pass************" + proxy['ip_port']
                request.meta['proxy'] = to_bytes("http://%s" % proxy['ip_port'])

    DOWNLOADER_MIDDLEWARES = {
       'step8_king.middlewares.ProxyMiddleware': 500,
    }

"""

"""
20. Https访问
    Https访问时有两种状况：
    1. 要爬取网站使用的可信任证书(默认支持)
        DOWNLOADER_HTTPCLIENTFACTORY = "scrapy.core.downloader.webclient.ScrapyHTTPClientFactory"
        DOWNLOADER_CLIENTCONTEXTFACTORY = "scrapy.core.downloader.contextfactory.ScrapyClientContextFactory"

    2. 要爬取网站使用的自定义证书
        DOWNLOADER_HTTPCLIENTFACTORY = "scrapy.core.downloader.webclient.ScrapyHTTPClientFactory"
        DOWNLOADER_CLIENTCONTEXTFACTORY = "step8_king.https.MySSLFactory"

        # https.py
        from scrapy.core.downloader.contextfactory import ScrapyClientContextFactory
        from twisted.internet.ssl import (optionsForClientTLS, CertificateOptions, PrivateCertificate)

        class MySSLFactory(ScrapyClientContextFactory):
            def getCertificateOptions(self):
                from OpenSSL import crypto
                v1 = crypto.load_privatekey(crypto.FILETYPE_PEM, open('/Users/wupeiqi/client.key.unsecure', mode='r').read())
                v2 = crypto.load_certificate(crypto.FILETYPE_PEM, open('/Users/wupeiqi/client.pem', mode='r').read())
                return CertificateOptions(
                    privateKey=v1,  # pKey对象
                    certificate=v2,  # X509对象
                    verify=False,
                    method=getattr(self, 'method', getattr(self, '_ssl_method', None))
                )
    其余：
        相关类
            scrapy.core.downloader.handlers.http.HttpDownloadHandler
            scrapy.core.downloader.webclient.ScrapyHTTPClientFactory
            scrapy.core.downloader.contextfactory.ScrapyClientContextFactory
        相关配置
            DOWNLOADER_HTTPCLIENTFACTORY
            DOWNLOADER_CLIENTCONTEXTFACTORY

"""



"""
21. 爬虫中间件
    class SpiderMiddleware(object):

        def process_spider_input(self,response, spider):
            '''
            下载完成，执行，而后交给parse处理
            :param response: 
            :param spider: 
            :return: 
            '''
            pass

        def process_spider_output(self,response, result, spider):
            '''
            spider处理完成，返回时调用
            :param response:
            :param result:
            :param spider:
            :return: 必须返回包含 Request 或 Item 对象的可迭代对象(iterable)
            '''
            return result

        def process_spider_exception(self,response, exception, spider):
            '''
            异常调用
            :param response:
            :param exception:
            :param spider:
            :return: None,继续交给后续中间件处理异常；含 Response 或 Item 的可迭代对象(iterable)，交给调度器或pipeline
            '''
            return None


        def process_start_requests(self,start_requests, spider):
            '''
            爬虫启动时调用
            :param start_requests:
            :param spider:
            :return: 包含 Request 对象的可迭代对象
            '''
            return start_requests

    内置爬虫中间件：
        'scrapy.contrib.spidermiddleware.httperror.HttpErrorMiddleware': 50,
        'scrapy.contrib.spidermiddleware.offsite.OffsiteMiddleware': 500,
        'scrapy.contrib.spidermiddleware.referer.RefererMiddleware': 700,
        'scrapy.contrib.spidermiddleware.urllength.UrlLengthMiddleware': 800,
        'scrapy.contrib.spidermiddleware.depth.DepthMiddleware': 900,

"""
# from scrapy.contrib.spidermiddleware.referer import RefererMiddleware
# Enable or disable spider middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
SPIDER_MIDDLEWARES = {
   # 'step8_king.middlewares.SpiderMiddleware': 543,
}


"""
22. 下载中间件
    class DownMiddleware1(object):
        def process_request(self, request, spider):
            '''
            请求须要被下载时，通过全部下载器中间件的process_request调用
            :param request:
            :param spider:
            :return:
                None,继续后续中间件去下载；
                Response对象，中止process_request的执行，开始执行process_response
                Request对象，中止中间件的执行，将Request从新调度器
                raise IgnoreRequest异常，中止process_request的执行，开始执行process_exception
            '''
            pass



        def process_response(self, request, response, spider):
            '''
            spider处理完成，返回时调用
            :param response:
            :param result:
            :param spider:
            :return:
                Response 对象：转交给其余中间件process_response
                Request 对象：中止中间件，request会被从新调度下载
                raise IgnoreRequest 异常：调用Request.errback
            '''
            print('response1')
            return response

        def process_exception(self, request, exception, spider):
            '''
            当下载处理器(download handler)或 process_request() (下载中间件)抛出异常
            :param response:
            :param exception:
            :param spider:
            :return:
                None：继续交给后续中间件处理异常；
                Response对象：中止后续process_exception方法
                Request对象：中止中间件，request将会被从新调用下载
            '''
            return None


    默认下载中间件
    {
        'scrapy.contrib.downloadermiddleware.robotstxt.RobotsTxtMiddleware': 100,
        'scrapy.contrib.downloadermiddleware.httpauth.HttpAuthMiddleware': 300,
        'scrapy.contrib.downloadermiddleware.downloadtimeout.DownloadTimeoutMiddleware': 350,
        'scrapy.contrib.downloadermiddleware.useragent.UserAgentMiddleware': 400,
        'scrapy.contrib.downloadermiddleware.retry.RetryMiddleware': 500,
        'scrapy.contrib.downloadermiddleware.defaultheaders.DefaultHeadersMiddleware': 550,
        'scrapy.contrib.downloadermiddleware.redirect.MetaRefreshMiddleware': 580,
        'scrapy.contrib.downloadermiddleware.httpcompression.HttpCompressionMiddleware': 590,
        'scrapy.contrib.downloadermiddleware.redirect.RedirectMiddleware': 600,
        'scrapy.contrib.downloadermiddleware.cookies.CookiesMiddleware': 700,
        'scrapy.contrib.downloadermiddleware.httpproxy.HttpProxyMiddleware': 750,
        'scrapy.contrib.downloadermiddleware.chunked.ChunkedTransferMiddleware': 830,
        'scrapy.contrib.downloadermiddleware.stats.DownloaderStats': 850,
        'scrapy.contrib.downloadermiddleware.httpcache.HttpCacheMiddleware': 900,
    }

"""
# from scrapy.contrib.downloadermiddleware.httpauth import HttpAuthMiddleware
# Enable or disable downloader middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
# DOWNLOADER_MIDDLEWARES = {
#    'step8_king.middlewares.DownMiddleware1': 100,
#    'step8_king.middlewares.DownMiddleware2': 500,
# }