Hello Temur, I want it to set doctor = True only if I create a new partner from my new menuitem action.

ok then. in such case you can set default value for doctor field using function. my answer is still valid in this conditions.

you can implement function that assigns default value as follows:

def compute_default_value_of_doctor(self):
    return self.env.context.get('doctor_default', False)

in your action set 'doctor_default' in context....

of course you've to add

default=compute_default_value_of_doctor

Works great! Thank you!