permissions : in django rest framework

I m working on django rest framework. I m having problems on permissions. I want to give GET And POST permission to admin user and only POST permission to other users(authentic). So far i have written the following code:

pemisssions.py

class UserAccessPermission(permissions.BasePermission):
    def has_permission(self, request, view):
        if request.method == 'GET' or request.method == 'POST':
            return request.user and request.user.is_staff
        if request.method == 'POST':
            return request.user and request.user.is_authenticated()

This code is not working as expected. Only admin users are able to GET and POST. And others users are not getting any kind of permission.

Guys help. Thanks in advance.

EDITED

class UserAccessPermission(permissions.BasePermission):
    def has_permission(self, request, view):
        if request.method == 'POST':
            return request.user and request.user.is_authenticated()
        elif request.method == 'GET':
            return request.user and request.user.is_staff