title: Python type inference and autocompletion inside map/filter/reduce with PyCharm
body: <p>PyCharm does a good job with method suggestions and autocompletion when it can infer the variable type, and when it can't I can usually add type hints to get autocompletion to work.  But I can't find a way to get PyCharm to infer the type inside map, filter, reduce.  Example:</p>
  <pre><code>l1 = [&quot;foo&quot;, &quot;bar&quot;, &quot;baz&quot;]
  l2 = list(map(lambda s: s.capitalize(), l1))
  </code></pre>
  <p>Would really like to be able to type <code>s.</code> and have PyCharm popup suggestions.  Is there a way?  I know lambdas do not allow type hints.</p>