title: Importing an item makes my spider unfindable?
body: <p>My problem is that a spider seems not to be found by the scrapy framework for some reason. I got this spider : </p>
  
  <pre><code>import scrapy
  from scrapy.http import Request
  from propreties.items import htmltableitem
  
  
  class SymbolspiderSpider(scrapy.Spider):
      name = "symbolspider"
  
      def start_requests(self):
          for i in range(0,10):
              yield Request( 'https://www.google.com/finance?q=%27&amp;restype=company&amp;noIL=1&amp;num=50&amp;ei=VPBjWJHKK9S7U6_dmvgM&amp;start='+str(i) )
  
      def parse(self, response):
          l=ItemLoader(item=htmltableitem(), response=response)
          l.add_xpath('htmltable', ".//*[@id='gf-viewc']/div/div[2]/form/table/tbody/child::*")
          return l.load_item()
  </code></pre>
  
  <p>When I run <code>scrapy crawl symbolspider -o output.csv</code> it errors with :</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/bin/scrapy", line 11, in &lt;module&gt;
      sys.exit(execute())
    File "/usr/lib/python3.5/site-packages/scrapy/cmdline.py", line 142, in execute
      _run_print_help(parser, _run_command, cmd, args, opts)
    File "/usr/lib/python3.5/site-packages/scrapy/cmdline.py", line 88, in _run_print_help
      func(*a, **kw)
    File "/usr/lib/python3.5/site-packages/scrapy/cmdline.py", line 149, in _run_command
      cmd.run(args, opts)
    File "/usr/lib/python3.5/site-packages/scrapy/commands/crawl.py", line 57, in run
      self.crawler_process.crawl(spname, **opts.spargs)
    File "/usr/lib/python3.5/site-packages/scrapy/crawler.py", line 162, in crawl
      crawler = self.create_crawler(crawler_or_spidercls)
    File "/usr/lib/python3.5/site-packages/scrapy/crawler.py", line 190, in create_crawler
      return self._create_crawler(crawler_or_spidercls)
    File "/usr/lib/python3.5/site-packages/scrapy/crawler.py", line 194, in _create_crawler
      spidercls = self.spider_loader.load(spidercls)
    File "/usr/lib/python3.5/site-packages/scrapy/spiderloader.py", line 51, in load
      raise KeyError("Spider not found: {}".format(spider_name))
  KeyError: 'Spider not found: symbolspider'
  </code></pre>
  
  <p>Funny thing is when I remove the line <code>from propreties.items import htmltableitem</code> it now detects the spider but just yields an error due to the fact that the items calls are unknown. What is happening ?</p>
  
  <p>Edit : <code>scrapy list</code> returns </p>
  
  <pre><code>/usr/lib/python3.5/site-packages/scrapy/spiderloader.py:37: RuntimeWarning: 
  Traceback (most recent call last):
    File "/usr/lib/python3.5/site-packages/scrapy/spiderloader.py", line 31, in _load_all_spiders
      for module in walk_modules(name):
    File "/usr/lib/python3.5/site-packages/scrapy/utils/misc.py", line 71, in walk_modules
      submod = import_module(fullpath)
    File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File "&lt;frozen importlib._bootstrap&gt;", line 986, in _gcd_import
    File "&lt;frozen importlib._bootstrap&gt;", line 969, in _find_and_load
    File "&lt;frozen importlib._bootstrap&gt;", line 958, in _find_and_load_unlocked
    File "&lt;frozen importlib._bootstrap&gt;", line 673, in _load_unlocked
    File "&lt;frozen importlib._bootstrap_external&gt;", line 665, in exec_module
    File "&lt;frozen importlib._bootstrap&gt;", line 222, in _call_with_frames_removed
    File "/home/volt/projects/scrapy/googlefinance/googlefinance/spiders/symbolspider.py", line 4, in &lt;module&gt;
      from propreties.items import htmltableitem
  ImportError: No module named 'propreties'
  Could not load spiders from module 'googlefinance.spiders'. Check SPIDER_MODULES setting
    warnings.warn(msg, RuntimeWarning)
  </code></pre>
  
  <p>And <code>tree</code> : </p>
  
  <pre><code>├── googlefinance
  │   ├── __init__.py
  │   ├── items.py
  │   ├── middlewares.py
  │   ├── pipelines.py
  │   ├── __pycache__
  │   │   ├── __init__.cpython-35.pyc
  │   │   └── settings.cpython-35.pyc
  │   ├── settings.py
  │   └── spiders
  │       ├── dataspider.py
  │       ├── __init__.py
  │       ├── __pycache__
  │       │   ├── dataspider.cpython-35.pyc
  │       │   ├── __init__.cpython-35.pyc
  │       │   └── symbolspider.cpython-35.pyc
  │       └── symbolspider.py
  ├── logs
  ├── output
  │   └── htmltables.csv
  └── scrapy.cfg
  </code></pre>