Where to write new method of python. Either in existing .py files or I need to create a new one?

Question

I am going to write a method in point of sale containing existing .py files. Should I create new python file ? or write new method in existing .py files??

Answer 1

If you need to add a new method to a particular model (e.g. sale.order), then inherit that particular model and add your method in a separate module i.e. custom module.

class SaleOrder(models.Model):
    _inherit='sale.order'
    @api.multi
    def custom_test_method(self...)

Note: This is in order to migrate to new version or update your code from github. Mostly, any modification to your model needs to be done in a custom module only.