python scrapy项目下spiders内多个爬虫同时运行

一般创建了scrapy文件夹后，可能需要写多个爬虫，如果想让它们同时运行而不是顺次运行的话，得怎么做？

a、在spiders目录的同级目录下创建一个commands目录，并在该目录中创建一个crawlall.py，将scrapy源代码里的commands文件夹里的crawl.py源码复制过来，只修改run()方法即可！

 1 import os
 2 from scrapy.commands import ScrapyCommand
 3 from scrapy.utils.conf import arglist_to_dict
 4 from scrapy.utils.python import without_none_values
 5 from scrapy.exceptions import UsageError
 6  
 7 class Command(ScrapyCommand):
 8     requires_project = True
 9     def syntax(self):
10         return "[options] <spider>"
11     def short_desc(self):
12         return "Run all spider"
13     def add_options(self, parser):
14         ScrapyCommand.add_options(self, parser)
15         parser.add_option("-a", dest="spargs", action="append", default=[], metavar="NAME=VALUE",
16                           help="set spider argument (may be repeated)")
17         parser.add_option("-o", "--output", metavar="FILE",
18                           help="dump scraped items into FILE (use - for stdout)")
19         parser.add_option("-t", "--output-format", metavar="FORMAT",
20                           help="format to use for dumping items with -o")
21  
22     def process_options(self, args, opts):
23         ScrapyCommand.process_options(self, args, opts)
24         try:
25             opts.spargs = arglist_to_dict(opts.spargs)
26         except ValueError:
27             raise UsageError("Invalid -a value, use -a NAME=VALUE", print_help=False)
28         if opts.output:
29             if opts.output == '-':
30                 self.settings.set('FEED_URI', 'stdout:', priority='cmdline')
31             else:
32                 self.settings.set('FEED_URI', opts.output, priority='cmdline')
33             feed_exporters = without_none_values(
34                 self.settings.getwithbase('FEED_EXPORTERS'))
35             valid_output_formats = feed_exporters.keys()
36             if not opts.output_format:
37                 opts.output_format = os.path.splitext(opts.output)[1].replace(".", "")
38             if opts.output_format not in valid_output_formats:
39                 raise UsageError("Unrecognized output format '%s', set one"
40                                  " using the '-t' switch or as a file extension"
41                                  " from the supported list %s" % (opts.output_format,
42                                                                   tuple(valid_output_formats)))
43             self.settings.set('FEED_FORMAT', opts.output_format, priority='cmdline')
44  
45     def run(self, args, opts):
46         #获取爬虫列表
47         spd_loader_list=self.crawler_process.spider_loader.list()#获取所有的爬虫文件。
48         print(spd_loader_list)
49         #遍历各爬虫
50         for spname in spd_loader_list or args:
51             self.crawler_process.crawl(spname, **opts.spargs)
52             print ('此时启动的爬虫为：'+spname)
53         self.crawler_process.start()