The callback... is a multi-output. Expected the output type to be a list or tuple but got:

Hi @NaveenKumar
Welcome to Dash, the main error message is:
“The callback …piechart.figure… is a multi-output. Expected the output type to be a list or tuple but got:”

And this is because your Output in the callback decorator is inside a list.

[Output(‘piechart’, ‘figure’)],

It should only be inside a list if there are multiple Outputs. You have only one, so take out the list brackets.

Side note: it’s very hard to read your code and the post. Refer to How to get Your Questions answered on the Plotly Forum to learn to write cleaner posts, which will help you get more replys.

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