Source code for hypothesis.extra.dateutil

# 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[dateutil]
--------------------

This module provides :pypi:`dateutil <python-dateutil>` timezones.

You can use this strategy to make :func:`~hypothesis.strategies.datetimes`
and :func:`~hypothesis.strategies.times` produce timezone-aware values.
"""

import datetime as dt

from dateutil import tz, zoneinfo  # type: ignore

from hypothesis import strategies as st
from hypothesis.strategies._internal.utils import cacheable, defines_strategy

__all__ = ["timezones"]


def __zone_sort_key(zone):
    """Sort by absolute UTC offset at reference date,
    positive first, with ties broken by name.
    """
    assert zone is not None
    offset = zone.utcoffset(dt.datetime(2000, 1, 1))
    offset = 999 if offset is None else offset
    return (abs(offset), -offset, str(zone))


[docs]@cacheable @defines_strategy() def timezones() -> st.SearchStrategy[dt.tzinfo]: """Any timezone from :pypi:`dateutil <python-dateutil>`. This strategy minimises to UTC, or the timezone with the smallest offset from UTC as of 2000-01-01, and is designed for use with :py:func:`~hypothesis.strategies.datetimes`. Note that the timezones generated by the strategy may vary depending on the configuration of your machine. See the dateutil documentation for more information. """ all_timezones = sorted( (tz.gettz(t) for t in zoneinfo.get_zonefile_instance().zones), key=__zone_sort_key, ) all_timezones.insert(0, tz.UTC) # We discard Nones in the list comprehension because Mypy knows that # tz.gettz may return None. However this should never happen for known # zone names, so we assert that it's impossible first. assert None not in all_timezones return st.sampled_from([z for z in all_timezones if z is not None])