I had the same question on a Windows computer, and started the Django server with python manage.py runserver 192.168.1.146:80, instead of the 0.0.0.0. (I used a different IP address of course).
After that, a Windows Firewall dialog popped up and asked if I should unblock the port (yes). Other computers in the LAN could then access the Django server using 192.168.1.146:80.