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Diffstat (limited to 'src/pytz/__init__.py')
| -rw-r--r-- | src/pytz/__init__.py | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/src/pytz/__init__.py b/src/pytz/__init__.py new file mode 100644 index 0000000..50c5b55 --- /dev/null +++ b/src/pytz/__init__.py @@ -0,0 +1,516 @@ +''' +datetime.tzinfo timezone definitions generated from the +Olson timezone database: + + ftp://elsie.nci.nih.gov/pub/tz*.tar.gz + +See the datetime section of the Python Library Reference for information +on how to use these modules. +''' + +import sys +import datetime +import os.path + +from pytz.exceptions import AmbiguousTimeError +from pytz.exceptions import InvalidTimeError +from pytz.exceptions import NonExistentTimeError +from pytz.exceptions import UnknownTimeZoneError +from pytz.lazy import LazyDict, LazyList, LazySet # noqa +from pytz.tzinfo import unpickler, BaseTzInfo +from pytz.tzfile import build_tzinfo + + +# The IANA (nee Olson) database is updated several times a year. +OLSON_VERSION = '2021c' +VERSION = '2021.3' # pip compatible version number. +__version__ = VERSION + +OLSEN_VERSION = OLSON_VERSION # Old releases had this misspelling + +__all__ = [ + 'timezone', 'utc', 'country_timezones', 'country_names', + 'AmbiguousTimeError', 'InvalidTimeError', + 'NonExistentTimeError', 'UnknownTimeZoneError', + 'all_timezones', 'all_timezones_set', + 'common_timezones', 'common_timezones_set', + 'BaseTzInfo', 'FixedOffset', +] + + +if sys.version_info[0] > 2: # Python 3.x + + # Python 3.x doesn't have unicode(), making writing code + # for Python 2.3 and Python 3.x a pain. + unicode = str + + def ascii(s): + r""" + >>> ascii('Hello') + 'Hello' + >>> ascii('\N{TRADE MARK SIGN}') #doctest: +IGNORE_EXCEPTION_DETAIL + Traceback (most recent call last): + ... + UnicodeEncodeError: ... + """ + if type(s) == bytes: + s = s.decode('ASCII') + else: + s.encode('ASCII') # Raise an exception if not ASCII + return s # But the string - not a byte string. + +else: # Python 2.x + + def ascii(s): + r""" + >>> ascii('Hello') + 'Hello' + >>> ascii(u'Hello') + 'Hello' + >>> ascii(u'\N{TRADE MARK SIGN}') #doctest: +IGNORE_EXCEPTION_DETAIL + Traceback (most recent call last): + ... + UnicodeEncodeError: ... + """ + return s.encode('ASCII') + + +def open_resource(name): + """Open a resource from the zoneinfo subdir for reading. + + Uses the pkg_resources module if available and no standard file + found at the calculated location. + + It is possible to specify different location for zoneinfo + subdir by using the PYTZ_TZDATADIR environment variable. + """ + name_parts = name.lstrip('/').split('/') + for part in name_parts: + if part == os.path.pardir or os.path.sep in part: + raise ValueError('Bad path segment: %r' % part) + zoneinfo_dir = os.environ.get('PYTZ_TZDATADIR', None) + if zoneinfo_dir is not None: + filename = os.path.join(zoneinfo_dir, *name_parts) + else: + filename = os.path.join(os.path.dirname(__file__), + 'zoneinfo', *name_parts) + if not os.path.exists(filename): + # http://bugs.launchpad.net/bugs/383171 - we avoid using this + # unless absolutely necessary to help when a broken version of + # pkg_resources is installed. + try: + from pkg_resources import resource_stream + except ImportError: + resource_stream = None + + if resource_stream is not None: + return resource_stream(__name__, 'zoneinfo/' + name) + return open(filename, 'rb') + + +def resource_exists(name): + """Return true if the given resource exists""" + try: + if os.environ.get('PYTZ_SKIPEXISTSCHECK', ''): + # In "standard" distributions, we can assume that + # all the listed timezones are present. As an + # import-speed optimization, you can set the + # PYTZ_SKIPEXISTSCHECK flag to skip checking + # for the presence of the resource file on disk. + return True + open_resource(name).close() + return True + except IOError: + return False + + +_tzinfo_cache = {} + + +def timezone(zone): + r''' Return a datetime.tzinfo implementation for the given timezone + + >>> from datetime import datetime, timedelta + >>> utc = timezone('UTC') + >>> eastern = timezone('US/Eastern') + >>> eastern.zone + 'US/Eastern' + >>> timezone(unicode('US/Eastern')) is eastern + True + >>> utc_dt = datetime(2002, 10, 27, 6, 0, 0, tzinfo=utc) + >>> loc_dt = utc_dt.astimezone(eastern) + >>> fmt = '%Y-%m-%d %H:%M:%S %Z (%z)' + >>> loc_dt.strftime(fmt) + '2002-10-27 01:00:00 EST (-0500)' + >>> (loc_dt - timedelta(minutes=10)).strftime(fmt) + '2002-10-27 00:50:00 EST (-0500)' + >>> eastern.normalize(loc_dt - timedelta(minutes=10)).strftime(fmt) + '2002-10-27 01:50:00 EDT (-0400)' + >>> (loc_dt + timedelta(minutes=10)).strftime(fmt) + '2002-10-27 01:10:00 EST (-0500)' + + Raises UnknownTimeZoneError if passed an unknown zone. + + >>> try: + ... timezone('Asia/Shangri-La') + ... except UnknownTimeZoneError: + ... print('Unknown') + Unknown + + >>> try: + ... timezone(unicode('\N{TRADE MARK SIGN}')) + ... except UnknownTimeZoneError: + ... print('Unknown') + Unknown + + ''' + if zone is None: + raise UnknownTimeZoneError(None) + + if zone.upper() == 'UTC': + return utc + + try: + zone = ascii(zone) + except UnicodeEncodeError: + # All valid timezones are ASCII + raise UnknownTimeZoneError(zone) + + zone = _case_insensitive_zone_lookup(_unmunge_zone(zone)) + if zone not in _tzinfo_cache: + if zone in all_timezones_set: # noqa + fp = open_resource(zone) + try: + _tzinfo_cache[zone] = build_tzinfo(zone, fp) + finally: + fp.close() + else: + raise UnknownTimeZoneError(zone) + + return _tzinfo_cache[zone] + + +def _unmunge_zone(zone): + """Undo the time zone name munging done by older versions of pytz.""" + return zone.replace('_plus_', '+').replace('_minus_', '-') + + +_all_timezones_lower_to_standard = None + + +def _case_insensitive_zone_lookup(zone): + """case-insensitively matching timezone, else return zone unchanged""" + global _all_timezones_lower_to_standard + if _all_timezones_lower_to_standard is None: + _all_timezones_lower_to_standard = dict((tz.lower(), tz) for tz in all_timezones) # noqa + return _all_timezones_lower_to_standard.get(zone.lower()) or zone # noqa + + +ZERO = datetime.timedelta(0) +HOUR = datetime.timedelta(hours=1) + + +class UTC(BaseTzInfo): + """UTC + + Optimized UTC implementation. It unpickles using the single module global + instance defined beneath this class declaration. + """ + zone = "UTC" + + _utcoffset = ZERO + _dst = ZERO + _tzname = zone + + def fromutc(self, dt): + if dt.tzinfo is None: + return self.localize(dt) + return super(utc.__class__, self).fromutc(dt) + + def utcoffset(self, dt): + return ZERO + + def tzname(self, dt): + return "UTC" + + def dst(self, dt): + return ZERO + + def __reduce__(self): + return _UTC, () + + def localize(self, dt, is_dst=False): + '''Convert naive time to local time''' + if dt.tzinfo is not None: + raise ValueError('Not naive datetime (tzinfo is already set)') + return dt.replace(tzinfo=self) + + def normalize(self, dt, is_dst=False): + '''Correct the timezone information on the given datetime''' + if dt.tzinfo is self: + return dt + if dt.tzinfo is None: + raise ValueError('Naive time - no tzinfo set') + return dt.astimezone(self) + + def __repr__(self): + return "<UTC>" + + def __str__(self): + return "UTC" + + +UTC = utc = UTC() # UTC is a singleton + + +def _UTC(): + """Factory function for utc unpickling. + + Makes sure that unpickling a utc instance always returns the same + module global. + + These examples belong in the UTC class above, but it is obscured; or in + the README.rst, but we are not depending on Python 2.4 so integrating + the README.rst examples with the unit tests is not trivial. + + >>> import datetime, pickle + >>> dt = datetime.datetime(2005, 3, 1, 14, 13, 21, tzinfo=utc) + >>> naive = dt.replace(tzinfo=None) + >>> p = pickle.dumps(dt, 1) + >>> naive_p = pickle.dumps(naive, 1) + >>> len(p) - len(naive_p) + 17 + >>> new = pickle.loads(p) + >>> new == dt + True + >>> new is dt + False + >>> new.tzinfo is dt.tzinfo + True + >>> utc is UTC is timezone('UTC') + True + >>> utc is timezone('GMT') + False + """ + return utc + + +_UTC.__safe_for_unpickling__ = True + + +def _p(*args): + """Factory function for unpickling pytz tzinfo instances. + + Just a wrapper around tzinfo.unpickler to save a few bytes in each pickle + by shortening the path. + """ + return unpickler(*args) + + +_p.__safe_for_unpickling__ = True + + +class _CountryTimezoneDict(LazyDict): + """Map ISO 3166 country code to a list of timezone names commonly used + in that country. + + iso3166_code is the two letter code used to identify the country. + + >>> def print_list(list_of_strings): + ... 'We use a helper so doctests work under Python 2.3 -> 3.x' + ... for s in list_of_strings: + ... print(s) + + >>> print_list(country_timezones['nz']) + Pacific/Auckland + Pacific/Chatham + >>> print_list(country_timezones['ch']) + Europe/Zurich + >>> print_list(country_timezones['CH']) + Europe/Zurich + >>> print_list(country_timezones[unicode('ch')]) + Europe/Zurich + >>> print_list(country_timezones['XXX']) + Traceback (most recent call last): + ... + KeyError: 'XXX' + + Previously, this information was exposed as a function rather than a + dictionary. This is still supported:: + + >>> print_list(country_timezones('nz')) + Pacific/Auckland + Pacific/Chatham + """ + def __call__(self, iso3166_code): + """Backwards compatibility.""" + return self[iso3166_code] + + def _fill(self): + data = {} + zone_tab = open_resource('zone.tab') + try: + for line in zone_tab: + line = line.decode('UTF-8') + if line.startswith('#'): + continue + code, coordinates, zone = line.split(None, 4)[:3] + if zone not in all_timezones_set: # noqa + continue + try: + data[code].append(zone) + except KeyError: + data[code] = [zone] + self.data = data + finally: + zone_tab.close() + + +country_timezones = _CountryTimezoneDict() + + +class _CountryNameDict(LazyDict): + '''Dictionary proving ISO3166 code -> English name. + + >>> print(country_names['au']) + Australia + ''' + def _fill(self): + data = {} + zone_tab = open_resource('iso3166.tab') + try: + for line in zone_tab.readlines(): + line = line.decode('UTF-8') + if line.startswith('#'): + continue + code, name = line.split(None, 1) + data[code] = name.strip() + self.data = data + finally: + zone_tab.close() + + +country_names = _CountryNameDict() + + +# Time-zone info based solely on fixed offsets + +class _FixedOffset(datetime.tzinfo): + + zone = None # to match the standard pytz API + + def __init__(self, minutes): + if abs(minutes) >= 1440: + raise ValueError("absolute offset is too large", minutes) + self._minutes = minutes + self._offset = datetime.timedelta(minutes=minutes) + + def utcoffset(self, dt): + return self._offset + + def __reduce__(self): + return FixedOffset, (self._minutes, ) + + def dst(self, dt): + return ZERO + + def tzname(self, dt): + return None + + def __repr__(self): + return 'pytz.FixedOffset(%d)' % self._minutes + + def localize(self, dt, is_dst=False): + '''Convert naive time to local time''' + if dt.tzinfo is not None: + raise ValueError('Not naive datetime (tzinfo is already set)') + return dt.replace(tzinfo=self) + + def normalize(self, dt, is_dst=False): + '''Correct the timezone information on the given datetime''' + if dt.tzinfo is self: + return dt + if dt.tzinfo is None: + raise ValueError('Naive time - no tzinfo set') + return dt.astimezone(self) + + +def FixedOffset(offset, _tzinfos={}): + """return a fixed-offset timezone based off a number of minutes. + + >>> one = FixedOffset(-330) + >>> one + pytz.FixedOffset(-330) + >>> str(one.utcoffset(datetime.datetime.now())) + '-1 day, 18:30:00' + >>> str(one.dst(datetime.datetime.now())) + '0:00:00' + + >>> two = FixedOffset(1380) + >>> two + pytz.FixedOffset(1380) + >>> str(two.utcoffset(datetime.datetime.now())) + '23:00:00' + >>> str(two.dst(datetime.datetime.now())) + '0:00:00' + + The datetime.timedelta must be between the range of -1 and 1 day, + non-inclusive. + + >>> FixedOffset(1440) + Traceback (most recent call last): + ... + ValueError: ('absolute offset is too large', 1440) + + >>> FixedOffset(-1440) + Traceback (most recent call last): + ... + ValueError: ('absolute offset is too large', -1440) + + An offset of 0 is special-cased to return UTC. + + >>> FixedOffset(0) is UTC + True + + There should always be only one instance of a FixedOffset per timedelta. + This should be true for multiple creation calls. + + >>> FixedOffset(-330) is one + True + >>> FixedOffset(1380) is two + True + + It should also be true for pickling. + + >>> import pickle + >>> pickle.loads(pickle.dumps(one)) is one + True + >>> pickle.loads(pickle.dumps(two)) is two + True + """ + if offset == 0: + return UTC + + info = _tzinfos.get(offset) + if info is None: + # We haven't seen this one before. we need to save it. + + # Use setdefault to avoid a race condition and make sure we have + # only one + info = _tzinfos.setdefault(offset, _FixedOffset(offset)) + + return info + + +FixedOffset.__safe_for_unpickling__ = True + + +def _test(): + import doctest + sys.path.insert(0, os.pardir) + import pytz + return doctest.testmod(pytz) + + +if __name__ == '__main__': + _test() |