django __str__返回非字符串（元组类型）

Question

solved. using m2m field.

models.py

class Student(models.Model):

Answer 1

Use this on Comment model:

def __str__(self):
    return self.created_by.first_name + ' ' + self.student.name

Also on Student model:

def __str__(self):
    return self.name + ' ' + self.campus

Answer 2

Redefine __str__ :

def __str__(self):
    return self.name+' '+self.campus