def _get_dev_port(backend, instance=None):
  port = os.environ.get(_get_dev_port_var(backend, instance), None)
  if port:
    return int(port)
  else:
    return None
Returns the port for a backend [instance] in the dev_appserver.
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/api/backends/backends.py/_get_dev_port