def _copy_headers(src, dest):
 for (k, v) in src.items():
  if (is_sys_or_user_meta('object', k) or is_object_transient_sysmeta(k) or (k.lower() == 'x-delete-at')):
   dest[k] = v

def _copy_headers ( src , dest ) : for ( k , v ) in src . items ( ) : if ( is_sys_or_user_meta ( 'object' , k ) or is_object_transient_sysmeta ( k ) or ( k . lower ( ) == 'x-delete-at' ) ) : dest [ k ] = v
will copy desired headers from src to dest .