# Source code for hypothesis.extra.pytz

    # coding=utf-8
    #
    # This file is part of Hypothesis, which may be found at
    # https://github.com/HypothesisWorks/hypothesis-python
    #
    # Most of this work is copyright (C) 2013-2017 David R. MacIver
    # (david@drmaciver.com), but it contains contributions by others. See
    # CONTRIBUTING.rst for a full list of people who may hold copyright, and
    # consult the git log if you need to determine who owns an individual
    # contribution.
    #
    # 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 http://mozilla.org/MPL/2.0/.
    #
    # END HEADER

    """This module provides ``pytz`` timezones.

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

    """

    from __future__ import division, print_function, absolute_import

    import datetime as dt

    import pytz

    import hypothesis.strategies as st

    __all__ = ['timezones']

    @st.cacheable
    @st.defines_strategy
    def timezones():
        """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
        :py:func:`hypothesis.strategies.datetimes`.

        """
        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 = [pytz.UTC] + sorted(
            (t for t in all_timezones if isinstance(t, pytz.tzfile.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)