NestedSelect example does not work

[itsgifnotjiff]

This NestedSelect tutorial does not work. It throws ValueError as is and I am really trying to make it work but I simply can't.

def list_options(level, value):
    if level == "time_step":
        options = {"Daily": list_options, "Monthly": list_options}
    elif level == "level_type":
        options = {f"{value['time_step']}_upper": list_options, f"{value['time_step']}_lower": list_options}
    else:
        options = [f"{value['level_type']}.json", f"{value['level_type']}.csv"]

    return options

pn.widgets.NestedSelect(
    options=list_options,
    levels=["time_step", "level_type", "file_type"],
)

[ahuang11]

Can you please share the error? It works fine for me.

[itsgifnotjiff]

This one might be on me. Ever since I upgraded to Panel 1.4.2 from 1.3.8 I have been having very exotic issues like not displaying widgets and ValueErrors. I would actually close this issue until someone else reports it as I have zero confidence blaming Panel for the mishap.