title: Bypass mypy's "Module has no attribute" on dynamic attribute setting
body: <p>I have the following code on <code>a.py</code>:</p>
  
  <pre><code>class Tags(enum.Flag):
      NONE = 0
  
      A = enum.auto()
      B = enum.auto()
      C = enum.auto()
  
  # Allow using tags.A instead of tags.Tags.A
  globals().update(Tags.__members__)
  </code></pre>
  
  <p>But when I use it on other files, mypy (rightfully) fails to identify the attributes:</p>
  
  <pre><code>import tags
  print(tags.A)  # Module has no attribute "A"
  </code></pre>
  
  <p>Is there any possible way to bypass this in Python 3.6?</p>
  
  <p>Known solutions (which are not good enough for my case):</p>
  
  <ul>
  <li>Use <code># type: ignore</code> every time you use <code>tags.A</code></li>
  <li>Use <code>tags.Tags.A</code></li>
  <li>Use <code>__getitem__</code> in the module level (Works only from Python 3.7)</li>
  </ul>