how to access my 127.0.0.1:8000 from android tablet
127.0.0.1 is a loopback address that means, roughly, "this device"; your PC and your android tablet are separate devices, so each of them has its own 127.0.0.1.  In other words, if you try to go to 127.0.0.1 on your Android tab, it's trying to connect to a webserver on the Android device, which is not what you want.
However, you should be able to connect over the wifi.  On your windows box, open a command prompt and execute ipconfig.  Somewhere in the output should be your windows box's address, probably 192.168.1.100 or something similar.  You tablet should be able to see the Django server at that address.
I am developing a webpage in django (on my pc with windows 7) and now i need to test some pages in tablet pcs. suddenly the thought came if i can have an access to my localhost in windows from android tablet. is that possible? I am in the same wifi connection in both devices at home. 
i read a lot questions and answers regarding this issue in stackoverflow and other places, but none of them gave me some concrete solutions. 
I have samsung tab 2 10.1 with android 4.0.4.
appreciate any help, thanks