title: Passing Python functions from YAML file
body: <p>I have a YAML script where the users can define some parameters. They can also state in the YAML file a custom function they want to apply. For example:</p>
  <pre><code>processes:
      args1: 10
      args2: 5
      funct: np.sum
  </code></pre>
  <p>This YAML will be passed to a function like this:</p>
  <pre><code>def custom_func(args1, args2, funct):
      return funct(args1, args2)
  </code></pre>
  <p>With the YAML example above, I expect <code>custom_func()</code> to execute <code>np.sum(10,5)</code>. How can I make the data in YAML file to be parsed as Callable? <code>eval()</code> probably does the job but it might have security issue. Is there any proper way? Thanks!</p>