@cvax -
Thanks for reporting @cvax! Yes, this is a typo, it is supposed to be
return {
'df_1': df_1.to_json(orient='split'),
'df_2': df_2.to_json(orient='split'),
'df_3': df_3.to_json(orient='split'),
}
(keys are supposed to be strings). Fixed in Fix typo (thanks @cvax!) · plotly/dash-docs@b033b8d · GitHub