Django“此字段为必填”尝试更新CustomUser

如何解决Django“此字段为必填”尝试更新CustomUser

在我的models.py中，我有这个：

class CustomUser(AbstractUser):
    USER_TYPE = ((1,'HOD'),(2,'Staff'),(3,'Student'))
    username = None
    email = models.EmailField(unique=True)
    ....

class Student(models.Model):
    admin = models.OnetoOneField(CustomUser,on_delete=models.CASCADE)
    gender = models.CharField(max_length=1,choices=GENDER)
    address = models.TextField()
    profile_pic = models.ImageField(upload_to='media')
    session_start_year = models.DateField(null=True)
    session_end_year = models.DateField(null=True)
    created_at = models.DateTimeField(auto_Now_add=True)
    updated_at = models.DateTimeField(auto_Now_add=True)

在我的forms.py中，我有这个：

class CustomUserForm(forms.ModelForm):
    email = forms.EmailField(required=True)
    first_name = forms.CharField(required=True)
    last_name = forms.CharField(required=True)
    password = forms.CharField(widget=forms.PasswordInput)
    widget = {
        'password': forms.Passwordinput()
    }

    def __init__(self,*args,**kwargs):
        super(CustomUserForm,self).__init__(*args,**kwargs)
        for visible in self.visible_fields():
            visible.field.widget.attrs['class'] = 'form-control'

    class Meta:
        model = CustomUser
        fields = ['first_name','last_name','email','password',]


class StudentForm(CustomUserForm):
    def __init__(self,**kwargs):
        super(StudentForm,**kwargs)
        for visible in self.visible_fields():
            visible.field.widget.attrs['class'] = 'form-control'

    class Meta(CustomUserForm.Meta):
        model = Student
        fields = CustomUserForm.Meta.fields + \
            ['course','gender','address','profile_pic','session_start_year','session_end_year']
        widgets = {
            'session_start_year': DateInput(attrs={'type': 'date'}),'session_end_year': DateInput(attrs={'type': 'date'}),}

通过将context = {'form': StudentForm()}传递到模板，我可以从中添加新学生。但是现在，我在尝试更新学生方面遇到问题。我可以将student对象作为instance传递给StudentForm()，但仅设置了['course','session_end_year']字段值。

如何设置CustomUserForm的初始值？
我想在更新时将password和profile_pic设置为可选（它说This field is required.；我是否需要另一个modelForm？
建议将CustomUserForm和StudentForm合并为一个表格，还是应该分开处理？