zoukankan      html  css  js  c++  java
  • scrapy crawl 源码修改 爬虫多开

    import os
    from scrapy.commands import ScrapyCommand
    from scrapy.utils.conf import arglist_to_dict
    from scrapy.utils.python import without_none_values
    from scrapy.exceptions import UsageError
    
    
    class Command(ScrapyCommand):
    
        requires_project = True
    
        def syntax(self):
            return "[options] <spider>"
      # 这里修改一点
        def short_desc(self):
            return "Run all spider"
    
        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)
            if opts.output:
                if opts.output == '-':
                    self.settings.set('FEED_URI', 'stdout:', priority='cmdline')
                else:
                    self.settings.set('FEED_URI', opts.output, priority='cmdline')
                feed_exporters = without_none_values(
                    self.settings.getwithbase('FEED_EXPORTERS'))
                valid_output_formats = feed_exporters.keys()
                if not opts.output_format:
                    opts.output_format = os.path.splitext(opts.output)[1].replace(".", "")
                if opts.output_format not in valid_output_formats:
                    raise UsageError("Unrecognized output format '%s', set one"
                                     " using the '-t' switch or as a file extension"
                                     " from the supported list %s" % (opts.output_format,
                                                                      tuple(valid_output_formats)))
                self.settings.set('FEED_FORMAT', opts.output_format, priority='cmdline')
        #关键是这里
        def run(self, args, opts):
            # 获取爬虫列表
            spd_loder_list = self.crawler_process.spider_loader.list()
            # 遍历各爬虫
            for spname in spd_loder_list or args:
                self.crawler_process.crawl(spname,**opts.spargs)
                print('此时启动的爬虫为:'+spname)
            self.crawler_process.start()

    放入项目目录,配置setting.py

    COMMANDS_MODULE = 'mypjt.mycommand'
    scrapy mycommand --nolog
  • 相关阅读:
    Java集合框架--List去重
    solr管理集合
    关于unix环境高级编程、Linux程序设计两部书浅谈
    ubuntu17.10安装lnmp安装包的核心问题-gcc版本、g++版本
    手机谷歌浏览器简洁处理方法
    Ubuntu当状态栏网络图标隐藏的解决方法汇总
    Ubuntu创建WiFi:16.0.4
    关于virtual box 虚拟机使用
    关于json转义中文
    xp 允许序列号
  • 原文地址:https://www.cnblogs.com/Erick-L/p/6835755.html
Copyright © 2011-2022 走看看