Pickling error for Graph, Node, Edge

[shadiakiki1986]

Bug report

Bug summary

Cannot pickle ipycytoscape graph

Code for reproduction

ex_json = {
    "nodes": [
        {"data": {"id": 0, "name": "A"}},
        {"data": {"id": 1, "name": "B"}},
        {"data": {"id": 2, "name": "C"}}
    ],
    "edges": [
        {"data": {"id": 3, "source": 0, "target": 1}},
        {"data": {"id": 4, "source": 0, "target": 2}},
    ]
}

import ipycytoscape
cyto = ipycytoscape.CytoscapeWidget()
cyto.graph.add_graph_from_json(ex_json)

# pickling code in "actual outcome" section below

Actual outcome

# import pickle
# pickle.dumps(cyto) # PicklingError: Can't pickle <function <lambda> at 0x7fb6da6009d0>: attribute lookup <lambda> on jupyter_client.session failed
# pickle.dumps(cyto.graph) # AttributeError: Can't pickle local object 'Mutable.instance_init.<locals>.callback'
# pickle.dumps(cyto.graph.nodes[0]) # PicklingError: Can't pickle <function <lambda> at 0x7fb6da6009d0>: attribute lookup <lambda> on jupyter_client.session failed
#pickle.dumps(cyto.graph.edges[0]) # PicklingError: Can't pickle <function <lambda> at 0x7fb6da6009d0>: attribute lookup <lambda> on jupyter_client.session failed

#import dill
#dill.dumps(cyto.graph.nodes[0]) # TypeError: cannot pickle '_hashlib.HASH' object

#import cloudpickle
#cloudpickle.dumps(cyto.graph.nodes[0]) # TypeError: cannot pickle '_hashlib.HASH' object

Expected outcome

Result of pickle

Version Info

• ipycytoscape version (import ipycytoscape; print(ipycytoscape.__version__)) : 1.2.2
• Python version: 3.8.10
• Jupyter(Lab) version:

!jupyter --version

Selected Jupyter core packages...
IPython          : 7.27.0
ipykernel        : 6.4.1
ipywidgets       : 7.6.5
jupyter_client   : 6.1.12
jupyter_core     : 4.8.1
jupyter_server   : 1.11.0
jupyterlab       : not installed
nbclient         : 0.5.4
nbconvert        : 6.1.0
nbformat         : 5.1.3
notebook         : 6.4.4
qtconsole        : not installed
traitlets        : 5.1.0

[MridulS]

It's not possible to pickle a widget object, this probably needs to be solved upstream.

[shadiakiki1986]

Ok, linking here for reference: jupyter-widgets/ipywidgets#2879

[marimeireles]

Thanks for pointing it to the right direction peeps. I personally didn't know that.