def _get_dev_port_var(backend, instance=None):
 port_var = ('BACKEND_PORT.%s' % str(backend).lower())
 if (instance is not None):
  port_var = ('%s.%d' % (port_var, instance))
 return port_var

def _get_dev_port_var ( backend , instance = None ) : port_var = ( 'BACKEND_PORT.%s' % str ( backend ) . lower ( ) ) if ( instance is not None ) : port_var = ( '%s.%d' % ( port_var , instance ) ) return port_var
return the environment variable for a backend port .