code: def interface_ip(iface):
      '''
      Return `iface` IPv4 addr or an error if `iface` does not exist
      '''
      iface_info, error = _get_iface_info(iface)
  
      if error is False:
          inet = iface_info.get(iface, {}).get('inet', None)
          return inet[0].get('address', '') if inet else ''
      else:
          return errof interface_ip(iface):
      '''
      Return `iface` IPv4 addr or an error if `iface` does not exist
      '''
      iface_info, error = _get_iface_info(iface)
  
      if error is False:
          inet = iface_info.get(iface, {}).get('inet', None)
          return inet[0].get('address', '') if inet else ''
      else:
          return error
docs: Return `iface` IPv4 addr or an error if `iface` does not exist