It's probably easier just to update python?
Pywallet does not run on python3. You need python 2.x to run pywallet.
I'm now getting an error "No such file or directory C:\Users\xxx\Appdata\Roaming\Bitcoin\__db.001" - do I need to install bitcoin-qt?
What are you trying to achieve with pywallet ?
If you want to use it regularly as a wallet (not advised) you do need core + blockchain synced.
But if you only want to dump your private keys, it is not required.
How (with what flags) are you starting pywallet ?