Hands-on operator.methodcaller vs getattr vs direct: real calls/s invoking methods on many objects, measured on Linux localhost today in this lab for SREs.
Hands-on itertools.groupby vs manual dict-of-lists: real records/s grouping pre-sorted key runs, measured on Linux localhost today in this lab for SREs.
Hands-on fnmatch.filter vs re.compile name-list filtering measured on Linux localhost.
Hands-on concurrent.futures as_completed vs wait lab with measured completion timing on Linux localhost.
Hands-on tarfile vs zipfile create+extract lab: real MB/s on a mixed small-file fixture (uncompressed tar vs zip), measured on Linux localhost for SREs.
Hands-on os.scandir vs listdir vs Path.iterdir lab: real entries/s for names and is_file on a synthetic tree, measured on Linux localhost (lab) for SREs.
Hands-on Decimal vs float cumulative sum lab: real ops/s plus a simple accuracy note (not financial advice), measured on Linux localhost (lab) for SREs.
Hands-on threading.local vs tid-keyed dict vs module-global lab: real ops/s for per-thread state access patterns, measured on Linux localhost for SREs.
