How can i update a choice value in Model Field

[Yash Garg]

in models.py i have choices in a field-

APPROVAL_CHOICES = (

        ('APPROVED', 'Approved'),

        ('PENDING','Pending'),

        ('REJECTED','Rejected'),

    )

approval_status = models.CharField(_("Approval Status"),max_length=8,null=False,blank=False,choices=APPROVAL_CHOICES, default='Approved')

i wants to update value of approval_status field from views.py-

if Splash.objects.filter(ip_address = ipaddress).exists():

obj.approval_status = 'Pending'

i also tried-

        obj.approval_status = obj.APPROVAL_CHOICES[1][1]

please suggest how can i update my approval_choices value from views.py.

Also, i'm unable to fetch session id using this statement- 

       obj.session_id = request.session.session_key

please also tell how can i fetch session key of  a user.

Thanks