# This file is part of Hypothesis, which may be found at # https://github.com/HypothesisWorks/hypothesis/ # # Copyright the Hypothesis Authors. # Individual contributors are listed in AUTHORS.rst and the git log. # # This Source Code Form is subject to the terms of the Mozilla Public License, # v. 2.0. If a copy of the MPL was not distributed with this file, You can # obtain one at https://mozilla.org/MPL/2.0/. """ ---------------- hypothesis[pytz] ---------------- This module provides :pypi:`pytz` timezones. If you are unable to use the stdlib :mod:`zoneinfo` module, e.g. via the :func:`hypothesis.strategies.timezones` strategy, you can use this strategy with :py:func:`hypothesis.strategies.datetimes` and :py:func:`hypothesis.strategies.times` to produce timezone-aware values. .. deprecated:: :mod:`zoneinfo` was added we intend to remove ``hypothesis.extra.pytz``, after libraries such as Pandas and Django complete their own migrations. """ import datetime as dt import pytz from pytz.tzfile import StaticTzInfo # type: ignore # considered private by typeshed from hypothesis import strategies as st from hypothesis.strategies._internal.utils import cacheable, defines_strategy __all__ = ["timezones"] @cacheable @defines_strategy() def timezones() -> st.SearchStrategy[dt.tzinfo]: """Any timezone in the Olsen database, as a pytz tzinfo object. This strategy minimises to UTC, or the smallest possible fixed offset, and is designed for use with :func:`hypothesis.strategies.datetimes`. .. tip:: Prefer the :func:`hypothesis.strategies.timezones` strategy, which uses the stdlib :mod:`zoneinfo` module and avoids `the many footguns in pytz <https://blog.ganssle.io/articles/2018/03/pytz-fastest-footgun.html>`__. """ all_timezones = [pytz.timezone(tz) for tz in pytz.all_timezones] # Some timezones have always had a constant offset from UTC. This makes # them simpler than timezones with daylight savings, and the smaller the # absolute offset the simpler they are. Of course, UTC is even simpler! static: list = [pytz.UTC] static += sorted( (t for t in all_timezones if isinstance(t, StaticTzInfo)), key=lambda tz: abs(tz.utcoffset(dt.datetime(2000, 1, 1))), ) # Timezones which have changed UTC offset; best ordered by name. dynamic = [tz for tz in all_timezones if tz not in static] return st.sampled_from(static + dynamic)