Django- Can only concatenate str (not "ManyRelatedManager") to str

Question

I am trying to save my model. But when I try to save my model I throws the following error

TypeError at /admin/user/teacher/add/
can only concatenate str (not "ManyRelatedManager") to str

My models.py file looks like this

class Class(models.Model):
 Class = models.CharField(max_length=50)
 section_choices = (('A','A'),('B','B'),('C','C'),('D','D'),('E','E'))
 Section = models.CharField(max_length=100, choices=section_choices)

 def __str__(self):
     return self.Class + "," + self.Section

class Subject(models.Model):
subject = models.CharField(max_length=100)

def __str__(self):
    return self.subject

class Teacher(models.Model):
 User = models.ForeignKey(User, on_delete=models.CASCADE)
 Subject = models.ManyToManyField(Subject)
 Name = models.CharField(max_length=50)
 Profile = models.ImageField(upload_to = upload_teacher_profile_to, default = 
 'defaults/teacher_profile.png')
 Class = models.ManyToManyField(Class)
 Number = models.IntegerField(blank=True)
 is_banned = models.BooleanField(default=False)

 def __str__(self):
     return self.Name + "of" + self.Class

Answer 1

Updated your Teacher Model def __str__(self) function to

def __str__(self):
    return f"{self.Name} of {[class for class in self.Class.all()]}"

Class is a ManyToManyField in the Teacher Model, ManyToManyFields can contain many objects, hence you cannot use self.Class

You can learn more about ManyToManyField here

Answer 2

Try with(in class Teacher):

def __str__(self):
    output=""
    for x in self.Class.all():
        output=output+' | '+str(x) 
    return output