Thanks Niyas Raphy

I understand that your coding allows to

a) filter the contacts according to the search condition

    (but I don't know how to write the condition itself (search['name', 'ilike', 'biblio'] creates an error)

and b) replaces the field 'category_id' with ' ' )

This means that if 2 or more categories are attached to the contact, they will all be erased: Is this correct?

I need to erase only one known category, leaving the others if any.

How to achieve this? (I have hundreds of contacts to clean!

Hi,

You can create a scheduled action for it and run it manually using the run manually button, after the use case just remove it. Create a scheduled action which executes the Python code and inside the Python code you can make the partner categories to empty based on the condition in code.

See the sample below,

Code:

partner_rec = env['res.partner'].search([])
# you can filter the unncessary partners using the condition in search
for partner in partner_rec:
  partner.write({'field_name': ''})

Thanks