title: Is it possible to change the value of a selection field dynamically in Odoo 10?
body: <p>I would like to have my selections depend on the value of a Char field, for instance, a Char field defined as such: </p>
  
  <pre><code>my_char = fields.Char("Enter Something", readonly = False)
  </code></pre>
  
  <p>so I suppose the selection field should call a function, something like "_get_value"</p>
  
  <pre><code>my_selection = fields.Selection(selection = ' _get_value')
  @api.model
  def _get_value(self):
      my_list = [('key1','value1')]
      #no idea how to assign the value of my_char to value1
      return my_list
  </code></pre>
  
  <p>Eventually, I would like to have the selections in the drop down list vary as the user input different strings in my_char.<br>
  Is this achievable in Odoo? Because if it's not, I should better start reorganizing my structure. Thanks a lot.</p>