title: Dictionary/set comprehensions inside of f-string
body: <p>Is it possible to have a dictionary or set comprehension inside of an f-string in python 3.6+? </p>
  
  <p>It seems syntactically impossible:</p>
  
  <pre><code>names = ['a', 'b', 'c']
  pks = [1, 2, 3]
  
  f"{{name : pk for name, pk in zip(names, pks)}}"
  </code></pre>
  
  <p>This will return:</p>
  
  <pre><code>{name : pk for name, pk in zip(names, pks)}
  </code></pre>
  
  <p>This is expected behavior, double brackets result in literal brackets in the output as the expression isn't evaluated.</p>
  
  <p>Has anyone found a workaround to allow for dictionary/set comprehensions inside of f-strings?</p>