RecursionError: maximum recursion depth exceeded odoo 12

Question

While editing notes and saving, I got error as:

 self[a[0]] = a[1] 
 RecursionError: maximum recursion depth exceeded

Code:

    notes = fields.Text('Terms', compute="_default_terms",inverse="_inverse_terms")

    @api.multi
    def _default_terms(self):
        terms = "\n\nPayment Terms:\nThis LPO is on the goods / services named and is governed by the below mentioned Terms and Conditions\n\
LPO is a must in order to start with the Job \n\
If the supplier fails to deliver on time and thereby resulting on the rejection or cancellation of job, MAI BLUE has the right to cancel the job and has no financial obligation towards the supplier, and if MN BLUE has already paid any down payment; the supplier must return it to the company immediately.\n\
MAI BLUE can demand an amendment / modification due to sub-standard / low quality products / services provided, at supplier's cost. if the supplier is unable to rectify the product before final delivery MAI BLUE has the right not to pay the balance amount and demand back any advance payments made for the job.\n\
Delays in delivery and/or delivering the goods not as per agreed quality / specifications will lead to job cancellation and/or 50% reduction in payment from MAI BLUE towards the supplier.\n\
Once the supplier submits their final Quotation, no changes in materials or specification will be accepted after the supplier confirms or submit his quotation. Any changes will be under the supplier's responsibility/cost.\n\
"
        self.notes = terms


    @api.multi
    def _inverse_terms(self):
        terms = "\n\nPayment Terms:\nThis LPO is on the goods / services named and is governed by the below mentioned Terms and Conditions\n\
    LPO is a must in order to start with the Job \n\
    If the supplier fails to deliver on time and thereby resulting on the rejection or cancellation of job, MAI BLUE has the right to cancel the job and has no financial obligation towards the supplier, and if MN BLUE has already paid any down payment; the supplier must return it to the company immediately.\n\
    MAI BLUE can demand an amendment / modification due to sub-standard / low quality products / services provided, at supplier's cost. if the supplier is unable to rectify the product before final delivery MAI BLUE has the right not to pay the balance amount and demand back any advance payments made for the job.\n\
    Delays in delivery and/or delivering the goods not as per agreed quality / specifications will lead to job cancellation and/or 50% reduction in payment from MAI BLUE towards the supplier.\n\
    Once the supplier submits their final Quotation, no changes in materials or specification will be accepted after the supplier confirms or submit his quotation. Any changes will be under the supplier's responsibility/cost.\n\
    "
        self.notes= terms

Answer 1

If you want to use an inverse method to change values of computed fields, the computed field should be computed on persistent and changeable values.

Otherwise, you get the effect/error you're seeing right now: Your field is computed on a string in code. So the inverse method should change the value on that string, which isn't possible (or very, very difficult).

Just define a default value or default method, like in Kenly's answer:

@api.model
def _default_terms(self):
    return "terms..."

notes = fields.Text('Terms', default=_default_terms)

Another good way would be defining a system parameter or configurable field on the company, which could be configured on a settings page, like a lot of other things in Odoo.

You can then get that value as default from that parameter or company field as default. That way, the default is changeable in Odoo itself.