Customise array in python file f

Hi,
I wanted to customise the array defined in python file in custom app. Can you please help me to overcome this query.

Best regards,
Tejas Gode

your question is not clear.

How to customise the array from the python file in erpnext

You have to access the Server Side where the ERPNext is running. In the server side python (.py) files you can customise array or any other data types.