There are two main functionalities in that this: scraping and replaying. You don’t need to deal with scraping if using the already-scraped traces.sqlite sqlite database. Besides that there are two scripts worth noting: one which replays a single notebook session, and one which replays a whole set of sessions after filtering based on some criteria
replay-session.py replays a single notebook session (given trace_id and
session_id, basically ids for the repository and per-repository session),
handling things like timeouts, figuring out packages that need installation,
coverting Python 2 to Python 3 using the 2to3 tool,
etc. It also counts the number of exceptions that occurred during replay;
probably worth filtering out sessions where more than ~5-10% of the cell
executions give an exception. There’s also a bunch of ancillary stuff in there
that’s specific to nbsafety, like counting how often the user picks a stale
cell for re-execution or a refresher cell; if just using the replay functionality
and not replicating nbsafety results, this can just be deleted. Note that it assumes
availability of tables replay_stats and replay_exception_stats in the traces.sqlite
database whose schemas must be manually generated; the PyCharm sqlite connector is
pretty good for this.
run-replay-experiments.py runs all the sessions through a filtering process
and replays all sessions that pass a filter. A bunch of the filtering criteria
were manually specified after seeing nonsensical sessions that were replayed.
It also accepts a --version argument; if you specify the same version, it skips
sessions that were already replayed; if you specify a new version, it starts
from scratch. There are also some nbsafety-specific parameters:
--naive-refresher-computation: is a baseline used in the paper,--forward-only-propagation: used to measure utility of highlights where new ones are only created in later cells (spacially relative to the currently executed one) instead of both earlier and later cells--no-nbsafety: used to determine how much faster non-nbsafety replay was (to see what nbsafety overhead was like).
When replaying these sessions, it is probably a good idea to do so in a chrooted environment or docker container, since the sessions are untrusted code that sometimes do some fairly strange things.