title: Django, tutorial - error: No module named urls
body: <p>Hi I am following the tutorial to make first web app by Django(<a href="https://docs.djangoproject.com/en/1.10/intro/tutorial01/#write-your-first-view" rel="nofollow noreferrer">link</a>)
  But I was given this error:</p>
  
  <pre><code> File "c:\Python27\lib\site-packages\django\utils\autoreload.py", line 226, in wrapper
      fn(*args, **kwargs)
     File "c:\Python27\lib\site-packages\django\core\management\commands\runserver.py", line 121, in inner_run
      self.check(display_num_errors=True)
     File "c:\Python27\lib\site-packages\django\core\management\base.py", line 374, in check
      include_deployment_checks=include_deployment_checks,
     File "c:\Python27\lib\site-packages\django\core\management\base.py", line 361, in _run_checks
      return checks.run_checks(**kwargs)
     File "c:\Python27\lib\site-packages\django\core\checks\registry.py", line 81, in run_checks
      new_errors = check(app_configs=app_configs)
     File "c:\Python27\lib\site-packages\django\core\checks\urls.py", line 14, in check_url_config
      return check_resolver(resolver)
     File "c:\Python27\lib\site-packages\django\core\checks\urls.py", line 24, in check_resolver
      for pattern in resolver.url_patterns:
     File "c:\Python27\lib\site-packages\django\utils\functional.py", line 35, in __get__
      res = instance.__dict__[self.name] = self.func(instance)
     File "c:\Python27\lib\site-packages\django\urls\resolvers.py", line 313, in url_patterns
      patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
     File "c:\Python27\lib\site-packages\django\utils\functional.py", line 35, in __get__
      res = instance.__dict__[self.name] = self.func(instance)
     File "c:\Python27\lib\site-packages\django\urls\resolvers.py", line 306, in urlconf_module
      return import_module(self.urlconf_name)
     File "c:\Python27\lib\importlib\__init__.py", line 37, in import_module
      __import__(name)
     File "c:\Python27\Proj\mysite\mysite\urls.py", line 7, in &lt;module&gt;
      url(r'^polls/', include('polls.urls'))
     File "c:\Python27\lib\site-packages\django\conf\urls\__init__.py", line 50, in include
      urlconf_module = import_module(urlconf_module)
     File "c:\Python27\lib\importlib\__init__.py", line 37, in import_module
      __import__(name) ImportError: No module named urls
  </code></pre>
  
  <p>I have read some answers here on SO, but they suggest that this error is caused by wrong version of framework, which is not my case.  My version of python is 2.7 and Djanog 1.10.1</p>
  
  <p>My urls.py</p>
  
  <pre><code>from django.conf.urls import url, include
  
  
  from django.contrib import admin
  
  urlpatterns = [
      url(r'^polls/', include('polls.urls'))    ]
  </code></pre>
  
  <p>Thank you.</p>
  
  <p>EDIT:</p>
  
  <p>File: polls/urls.py</p>
  
  <pre><code>from django.conf.urls import url
  
  from . import views
  
  urlpatterns = [
      url(r'^$', views.index, name='index'),
  ]
  </code></pre>
  
  <p>EDIT 2:</p>
  
  <p>Thank all for your comments. There is my file structure of the project.</p>
  
  <p><a href="https://i.stack.imgur.com/5eYEX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5eYEX.png" alt="enter image description here"></a></p>