db.py is a basic Python implementation of a transaction-based in-memory datastore, capable of storing key-value pairs.
All calls to get(key), set(key, value) and remove(key) are recorded in the log of the respective transaction block, which is created by begin(). We can then persist the changes by commit() and forget about them through rollback(). This implementation supports nesting of transaction blocks.
The testing harness test.py runs the tests in the /tests directory.