According to the (source) documentation, the weight property:
Attach a labelled weight to an object, which can subsequently be used in the algorithms keep_weight and drop_weight. See the documentation of those algorithms for examples.
Examples of it use can be found on the manual pages of the algorithms keep_weight and drop_weight
Question
Is it possible to get the weight of an object?
My question is inspire in the uses of algorithms like n_args or n_indices (See util.node).