Where should I get rpcuser.py from? I am following the instructions in my bitcoin.conf file, it writes:

It is set at intialization time
# using the output from the script in share/rpcuser/rpcuser.py after providing a username:
#
# ./share/rpcuser/rpcuser.py alice


However, I can't finde any rpcuser folder or rpcuser.py file. Am I supposed to have them? Is this normal? I already ran 

sudo apt-add-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install bitcoin-qt


So, if I don't have the file, where should I get it from? Does this mean my bitcoin installation is incomplete? I havent synced all the blockchain yet.. 

Anyway, any advice is welcome.
There is no rpcuser.py script anymore, it is now named rpcauth.py (the ppa may not be up to date). This file can be found in the Bitcoin Core source code repository: https://github.com/bitcoin/bitcoin/blob/master/share/rpcauth/rpcauth.py