AttributeError: 'module' object has no attribute 'DATABASE' when using scrapy shell

Question

我正在尝试运行我项目根目录中的 scrapy shell，但我一直收到关于某种数据库设置的模糊错误。我不确定这是 SQLAlchemy 的问题……还是我的模式定义有问题？

如果我运行 scrapy shell http://some_website.com 来自项目路径之外的任何其他目录，我没有问题。

正在尝试启动 shell:

me@me:~/my_spider$ scrapy shell http://some_website.com
2015-12-13 15:15:58-0800 [scrapy] INFO: Scrapy 0.24.4 started (bot: my_bot)
2015-12-13 15:15:58-0800 [scrapy] INFO: Optional features available: ssl, http11, boto, django
2015-12-13 15:15:58-0800 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'my_spider.spiders', 'DEPTH_LIMIT': 2, 'CONCURRENT_REQUESTS_PER_DOMAIN': 1, 'CONCURRENT_REQUESTS': 1, 'SPIDER_MODULES': [''my_spider.spiders'], 'BOT_NAME': 'my_bot', 'COOKIES_ENABLED': False, 'LOGSTATS_INTERVAL': 0, 'DOWNLOAD_DELAY': 5}
2015-12-13 15:15:58-0800 [scrapy] INFO: Enabled extensions: TelnetConsole, CloseSpider, WebService, CoreStats, SpiderState
2015-12-13 15:15:59-0800 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, RandomUserAgentMiddleware, ProxyMiddleware, RetryMiddleware, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, ChunkedTransferMiddleware, DownloaderStats
2015-12-13 15:15:59-0800 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware

这是追溯：

Traceback (most recent call last):
  File "/usr/local/bin/scrapy", line 11, in <module>
    sys.exit(execute())
  File "/usr/local/lib/python2.7/dist-packages/scrapy/cmdline.py", line 143, in execute
    _run_print_help(parser, _run_command, cmd, args, opts)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/cmdline.py", line 89, in _run_print_help
    func(*a, **kw)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/cmdline.py", line 150, in _run_command
    cmd.run(args, opts)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/commands/shell.py", line 46, in run
    self.crawler_process.start_crawling()
  File "/usr/local/lib/python2.7/dist-packages/scrapy/crawler.py", line 124, in start_crawling
    return self._start_crawler() is not None
  File "/usr/local/lib/python2.7/dist-packages/scrapy/crawler.py", line 139, in _start_crawler
    crawler.configure()
  File "/usr/local/lib/python2.7/dist-packages/scrapy/crawler.py", line 47, in configure
    self.engine = ExecutionEngine(self, self._spider_closed)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/core/engine.py", line 65, in __init__
    self.scraper = Scraper(crawler)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/core/scraper.py", line 66, in __init__
    self.itemproc = itemproc_cls.from_crawler(crawler)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/middleware.py", line 50, in from_crawler
    return cls.from_settings(crawler.settings, crawler)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/middleware.py", line 35, in from_settings
    mw = mwcls()
  File "~/my_spider/pipelines.py", line 14, in __init__
    engine = db_connect()
  File "~/my_spider/libs/database/__init__.py", line 14, in db_connect
    url = URL(**settings.DATABASE)
AttributeError: 'module' object has no attribute 'DATABASE'

如有任何建议，我们将不胜感激。

Answer 1

您有一个 settings scrapy 找到的变量定义，而不是它认为会找到（或需要）的变量定义。

它不是查找 scrapy/middleware.py 模块 from_settings() 调用正在使用的 settings 对象，而是查找您的设置对象并希望它提供 .DATABASE 属性.没有看到 my_bot 中的代码，TraceBack 和最近的 Python 2.7 scrapy 中的代码行：

 26     @classmethod
 27     def from_settings(cls, settings, crawler=None):
 28         mwlist = cls._get_mwlist_from_settings(settings)
 29         middlewares = []
 30         for clspath in mwlist:
 31             try:
 32                 mwcls = load_object(clspath)
 33                 if crawler and hasattr(mwcls, 'from_crawler'):
 34                     mw = mwcls.from_crawler(crawler)
 35                 elif hasattr(mwcls, 'from_settings'):
 36                     mw = mwcls.from_settings(settings)

建议对您不想要的设置对象进行方法解析，或者您按照教程提供了 from_settings() 但未实现所需的属性。

Answer 2

除了@tristan 指出的内容之外，根据回溯 - 当您启动 shell 时，Scrapy 会获取您的项目设置，其中包括管道，其中一个正在执行 db_connect() 函数，它使用 settings.DATABASE 设置：

url = URL(**settings.DATABASE)

确保您在项目设置中定义了 DATABASE 字典。

AttributeError: 'module' object has no attribute 'DATABASE' when using scrapy shell

AttributeError: 'module' object has no attribute 'DATABASE' when using scrapy shell

python

scrapy

scrapy-shell