Hi Niyas Raphy, Thanks for your answer! But I tried to inherit name_get function.
My code:
def name_get(self):
result = []
for record in self:
result.append((record.id, '%s' % record.partner_name))
return result

It was showing properly.
But I want to say, at the end of creating new data in the popup Create and Edit...
It displays the name, not partner_name.