@_FFI.callback(u'Value(ExternContext*, Key*)')
def extern_val_for(context_handle, key):
 c = _FFI.from_handle(context_handle)
 return c.key_to_value(key)

@ _FFI . callback ( u'Value(ExternContext*, Key*)' ) def extern_val_for ( context_handle , key ) : c = _FFI . from_handle ( context_handle ) return c . key_to_value ( key )
return a value for a key .