Unwanted side-effect of grid2op.Action.baseAction.as_dict method

[vinault]

Environment

• Grid2op version: 1.9.3
• System: Windows 10

Bug description

The as_dict method do not return the expected dictionnary for a specific action on the l2rpn_idf_2023 environment (see how to reproduce)

How to reproduce

import grid2op
from grid2op.Backend import PandaPowerBackend

env = grid2op.make(
    "l2rpn_idf_2023",
    backend=PandaPowerBackend(detailed_infos_for_cascading_failures=False),
)

act = {
    "set_bus": {
        "lines_or_id": [(0, 2)],
        "loads_id": [(0, 2)],
    },
}

topo_action = env.action_space(act)
print(topo_action.as_dict())

Current output

This returns :

{'set_bus_vect': {'nb_modif_objects': 2, '0': {'0': {'type': 'load', 'new_bus': 2}}, 'nb_modif_subs': 1, 'modif_subs_id': ['0']}}

Expected output

The expected return should look like

{'set_bus_vect': {'nb_modif_objects': 2, '0': {'0': {'type': 'load', 'new_bus': 2}, '??': {'type': 'line (origin)', 'new_bus': 2}}, 'nb_modif_subs': 1, 'modif_subs_id': ['0']}}

What I think is happening

When building the dictionnary in the as_dict method here

 '0': {'type': 'line (origin)', 'new_bus': 2}

is first inserted in

res["set_bus_vect"]["0"]

and then

 '0': {'type': 'load', 'new_bus': 2}

is inserted, thus overwriting the line information.

This comes from the fact that _obj_caract_from_topo_id (here) returns 0 as obj_id for both the line_or and the load, which is unfortunate.

Thank you very much for your help !