`import module` brings in a module namespace; `from module import name` brings a specific name into scope directly.
python import math from collections import Counter math.sqrt(16) Counter(["a", "b", "a"]).most_common(1)
Useful standard-library modules for this track include `json` (serialize/deserialize), `hashlib` (hashing), `re` (regex), `datetime` (dates/times), `itertools` (iterator tools), and `dataclasses` (structured records).
Every module has a special `__name__` variable; the idiom `if __name__ == "__main__":` guards code that should run only when the file is executed directly, not imported.