title: Azure Python Function: Underscore are not working in routes
body: <p>Hello i am creating an &quot;Azure Python Function&quot; with an POST/GET route in the UNC path like http://localhost:7071/api/indicator/sjz_jb_1. I create therefore the following code :</p>
  <p><strong>function.json</strong></p>
  <p>In the previous version I used <code>{indicator:alpa?}</code>  based on <a href="https://docs.microsoft.com/nl-nl/azure/azure-functions/functions-bindings-http-webhook-trigger?tabs=python#customize-the-http-endpoint" rel="nofollow noreferrer">https://docs.microsoft.com/nl-nl/azure/azure-functions/functions-bindings-http-webhook-trigger?tabs=python#customize-the-http-endpoint</a>. But with the alfa datatype the underscores are not working. After searching on the internet I found the stackoverflow post  <a href="https://stackoverflow.com/questions/24394109/underscore-in-url-not-working-with-attribute-routing">Underscore in URL not working with attribute routing</a> it was based on c# but the code was still working but still result in a page not found.</p>
  <pre><code>{
    &quot;scriptFile&quot;: &quot;__init__.py&quot;,
    &quot;bindings&quot;: [
      {
        &quot;authLevel&quot;: &quot;function&quot;,
        &quot;type&quot;: &quot;httpTrigger&quot;,
        &quot;direction&quot;: &quot;in&quot;,
        &quot;name&quot;: &quot;req&quot;,
        &quot;methods&quot;: [
          &quot;get&quot;,
          &quot;post&quot;
        ],
        &quot;route&quot;: &quot;indicator/{indicator:regex(^[a-zA-Z_]+$)}&quot;
      },
      {
        &quot;type&quot;: &quot;http&quot;,
        &quot;direction&quot;: &quot;out&quot;,
        &quot;name&quot;: &quot;$return&quot;
      }
    ]
  }
  </code></pre>
  <p><strong>init.py</strong></p>
  <pre><code>import logging
  import json
  import azure.functions as func
  from shared_code.Metadata import Visualisatieportal_indicatoren
  
  
  def main(req: func.HttpRequest) -&gt; func.HttpResponse:
      logging.info('Python HTTP trigger function processed a request.')
      ind = req.route_params.get('indicator')  
      logging.info(ind)
      indicator1 = Visualisatieportal_indicatoren.getVisualisatieportal_indicatoren(ind)
      result = json.dumps(indicator1.__dict__)
      return func.HttpResponse(str(id))
  </code></pre>
  <p>My question is, what do I need to change so the so underscores can support in the route of the endpoints.</p>
  <p>Manny thanks
  Erik</p>