diff options
| -rw-r--r-- | Doc/library/datetime.rst | 37 | ||||
| -rw-r--r-- | Doc/whatsnew/3.6.rst | 8 | ||||
| -rw-r--r-- | Lib/_strptime.py | 81 | ||||
| -rw-r--r-- | Lib/test/test_strptime.py | 57 | ||||
| -rw-r--r-- | Misc/NEWS | 3 |
5 files changed, 159 insertions, 27 deletions
diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst index 5c659e7..cf5d5b8 100644 --- a/Doc/library/datetime.rst +++ b/Doc/library/datetime.rst @@ -1909,6 +1909,34 @@ format codes. | ``%%`` | A literal ``'%'`` character. | % | | +-----------+--------------------------------+------------------------+-------+ +Several additional directives not required by the C89 standard are included for +convenience. These parameters all correspond to ISO 8601 date values. These +may not be available on all platforms when used with the :meth:`strftime` +method. The ISO 8601 year and ISO 8601 week directives are not interchangeable +with the year and week number directives above. Calling :meth:`strptime` with +incomplete or ambiguous ISO 8601 directives will raise a :exc:`ValueError`. + ++-----------+--------------------------------+------------------------+-------+ +| Directive | Meaning | Example | Notes | ++===========+================================+========================+=======+ +| ``%G`` | ISO 8601 year with century | 0001, 0002, ..., 2013, | \(8) | +| | representing the year that | 2014, ..., 9998, 9999 | | +| | contains the greater part of | | | +| | the ISO week (``%V``). | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%u`` | ISO 8601 weekday as a decimal | 1, 2, ..., 7 | | +| | number where 1 is Monday. | | | ++-----------+--------------------------------+------------------------+-------+ +| ``%V`` | ISO 8601 week as a decimal | 01, 02, ..., 53 | \(8) | +| | number with Monday as | | | +| | the first day of the week. | | | +| | Week 01 is the week containing | | | +| | Jan 4. | | | ++-----------+--------------------------------+------------------------+-------+ + +.. versionadded:: 3.6 + ``%G``, ``%u`` and ``%V`` were added. + Notes: (1) @@ -1973,7 +2001,14 @@ Notes: (7) When used with the :meth:`strptime` method, ``%U`` and ``%W`` are only used - in calculations when the day of the week and the year are specified. + in calculations when the day of the week and the calendar year (``%Y``) + are specified. + +(8) + Similar to ``%U`` and ``%W``, ``%V`` is only used in calculations when the + day of the week and the ISO year (``%G``) are specified in a + :meth:`strptime` format string. Also note that ``%G`` and ``%Y`` are not + interchangable. .. rubric:: Footnotes diff --git a/Doc/whatsnew/3.6.rst b/Doc/whatsnew/3.6.rst index 24fd822..dd35c9a 100644 --- a/Doc/whatsnew/3.6.rst +++ b/Doc/whatsnew/3.6.rst @@ -110,6 +110,14 @@ Private and special attribute names now are omitted unless the prefix starts with underscores. A space or a colon can be added after completed keyword. (Contributed by Serhiy Storchaka in :issue:`25011` and :issue:`25209`.) +datetime +-------- + +* :meth:`datetime.stftime <datetime.datetime.stftime>` and + :meth:`date.stftime <datetime.date.stftime>` methods now support ISO 8601 + date directives ``%G``, ``%u`` and ``%V``. + (Contributed by Ashley Anderson in :issue:`12006`.) + Optimizations ============= diff --git a/Lib/_strptime.py b/Lib/_strptime.py index 374923d..fe5b046 100644 --- a/Lib/_strptime.py +++ b/Lib/_strptime.py @@ -195,12 +195,15 @@ class TimeRE(dict): 'f': r"(?P<f>[0-9]{1,6})", 'H': r"(?P<H>2[0-3]|[0-1]\d|\d)", 'I': r"(?P<I>1[0-2]|0[1-9]|[1-9])", + 'G': r"(?P<G>\d\d\d\d)", 'j': r"(?P<j>36[0-6]|3[0-5]\d|[1-2]\d\d|0[1-9]\d|00[1-9]|[1-9]\d|0[1-9]|[1-9])", 'm': r"(?P<m>1[0-2]|0[1-9]|[1-9])", 'M': r"(?P<M>[0-5]\d|\d)", 'S': r"(?P<S>6[0-1]|[0-5]\d|\d)", 'U': r"(?P<U>5[0-3]|[0-4]\d|\d)", 'w': r"(?P<w>[0-6])", + 'u': r"(?P<u>[1-7])", + 'V': r"(?P<V>5[0-3]|0[1-9]|[1-4]\d|\d)", # W is set below by using 'U' 'y': r"(?P<y>\d\d)", #XXX: Does 'Y' need to worry about having less or more than @@ -295,6 +298,22 @@ def _calc_julian_from_U_or_W(year, week_of_year, day_of_week, week_starts_Mon): return 1 + days_to_week + day_of_week +def _calc_julian_from_V(iso_year, iso_week, iso_weekday): + """Calculate the Julian day based on the ISO 8601 year, week, and weekday. + ISO weeks start on Mondays, with week 01 being the week containing 4 Jan. + ISO week days range from 1 (Monday) to 7 (Sunday). + """ + correction = datetime_date(iso_year, 1, 4).isoweekday() + 3 + ordinal = (iso_week * 7) + iso_weekday - correction + # ordinal may be negative or 0 now, which means the date is in the previous + # calendar year + if ordinal < 1: + ordinal += datetime_date(iso_year, 1, 1).toordinal() + iso_year -= 1 + ordinal -= datetime_date(iso_year, 1, 1).toordinal() + return iso_year, ordinal + + def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): """Return a 2-tuple consisting of a time struct and an int containing the number of microseconds based on the input string and the @@ -339,15 +358,15 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): raise ValueError("unconverted data remains: %s" % data_string[found.end():]) - year = None + iso_year = year = None month = day = 1 hour = minute = second = fraction = 0 tz = -1 tzoffset = None # Default to -1 to signify that values not known; not critical to have, # though - week_of_year = -1 - week_of_year_start = -1 + iso_week = week_of_year = None + week_of_year_start = None # weekday and julian defaulted to None so as to signal need to calculate # values weekday = julian = None @@ -369,6 +388,8 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): year += 1900 elif group_key == 'Y': year = int(found_dict['Y']) + elif group_key == 'G': + iso_year = int(found_dict['G']) elif group_key == 'm': month = int(found_dict['m']) elif group_key == 'B': @@ -414,6 +435,9 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): weekday = 6 else: weekday -= 1 + elif group_key == 'u': + weekday = int(found_dict['u']) + weekday -= 1 elif group_key == 'j': julian = int(found_dict['j']) elif group_key in ('U', 'W'): @@ -424,6 +448,8 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): else: # W starts week on Monday. week_of_year_start = 0 + elif group_key == 'V': + iso_week = int(found_dict['V']) elif group_key == 'z': z = found_dict['z'] tzoffset = int(z[1:3]) * 60 + int(z[3:5]) @@ -444,28 +470,57 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): else: tz = value break + # Deal with the cases where ambiguities arize + # don't assume default values for ISO week/year + if year is None and iso_year is not None: + if iso_week is None or weekday is None: + raise ValueError("ISO year directive '%G' must be used with " + "the ISO week directive '%V' and a weekday " + "directive ('%A', '%a', '%w', or '%u').") + if julian is not None: + raise ValueError("Day of the year directive '%j' is not " + "compatible with ISO year directive '%G'. " + "Use '%Y' instead.") + elif week_of_year is None and iso_week is not None: + if weekday is None: + raise ValueError("ISO week directive '%V' must be used with " + "the ISO year directive '%G' and a weekday " + "directive ('%A', '%a', '%w', or '%u').") + else: + raise ValueError("ISO week directive '%V' is incompatible with " + "the year directive '%Y'. Use the ISO year '%G' " + "instead.") + leap_year_fix = False if year is None and month == 2 and day == 29: year = 1904 # 1904 is first leap year of 20th century leap_year_fix = True elif year is None: year = 1900 + + # If we know the week of the year and what day of that week, we can figure # out the Julian day of the year. - if julian is None and week_of_year != -1 and weekday is not None: - week_starts_Mon = True if week_of_year_start == 0 else False - julian = _calc_julian_from_U_or_W(year, week_of_year, weekday, - week_starts_Mon) - # Cannot pre-calculate datetime_date() since can change in Julian - # calculation and thus could have different value for the day of the week - # calculation. + if julian is None and weekday is not None: + if week_of_year is not None: + week_starts_Mon = True if week_of_year_start == 0 else False + julian = _calc_julian_from_U_or_W(year, week_of_year, weekday, + week_starts_Mon) + elif iso_year is not None and iso_week is not None: + year, julian = _calc_julian_from_V(iso_year, iso_week, weekday + 1) + if julian is None: + # Cannot pre-calculate datetime_date() since can change in Julian + # calculation and thus could have different value for the day of + # the week calculation. # Need to add 1 to result since first day of the year is 1, not 0. julian = datetime_date(year, month, day).toordinal() - \ datetime_date(year, 1, 1).toordinal() + 1 - else: # Assume that if they bothered to include Julian day it will - # be accurate. - datetime_result = datetime_date.fromordinal((julian - 1) + datetime_date(year, 1, 1).toordinal()) + else: # Assume that if they bothered to include Julian day (or if it was + # calculated above with year/week/weekday) it will be accurate. + datetime_result = datetime_date.fromordinal( + (julian - 1) + + datetime_date(year, 1, 1).toordinal()) year = datetime_result.year month = datetime_result.month day = datetime_result.day diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py index 346e2c6..6b26c8a 100644 --- a/Lib/test/test_strptime.py +++ b/Lib/test/test_strptime.py @@ -152,8 +152,8 @@ class TimeRETests(unittest.TestCase): "'%s' using '%s'; group 'a' = '%s', group 'b' = %s'" % (found.string, found.re.pattern, found.group('a'), found.group('b'))) - for directive in ('a','A','b','B','c','d','H','I','j','m','M','p','S', - 'U','w','W','x','X','y','Y','Z','%'): + for directive in ('a','A','b','B','c','d','G','H','I','j','m','M','p', + 'S','u','U','V','w','W','x','X','y','Y','Z','%'): compiled = self.time_re.compile("%" + directive) found = compiled.match(time.strftime("%" + directive)) self.assertTrue(found, "Matching failed on '%s' using '%s' regex" % @@ -218,6 +218,26 @@ class StrptimeTests(unittest.TestCase): else: self.fail("'%s' did not raise ValueError" % bad_format) + # Ambiguous or incomplete cases using ISO year/week/weekday directives + # 1. ISO week (%V) is specified, but the year is specified with %Y + # instead of %G + with self.assertRaises(ValueError): + _strptime._strptime("1999 50", "%Y %V") + # 2. ISO year (%G) and ISO week (%V) are specified, but weekday is not + with self.assertRaises(ValueError): + _strptime._strptime("1999 51", "%G %V") + # 3. ISO year (%G) and weekday are specified, but ISO week (%V) is not + for w in ('A', 'a', 'w', 'u'): + with self.assertRaises(ValueError): + _strptime._strptime("1999 51","%G %{}".format(w)) + # 4. ISO year is specified alone (e.g. time.strptime('2015', '%G')) + with self.assertRaises(ValueError): + _strptime._strptime("2015", "%G") + # 5. Julian/ordinal day (%j) is specified with %G, but not %Y + with self.assertRaises(ValueError): + _strptime._strptime("1999 256", "%G %j") + + def test_strptime_exception_context(self): # check that this doesn't chain exceptions needlessly (see #17572) with self.assertRaises(ValueError) as e: @@ -289,7 +309,7 @@ class StrptimeTests(unittest.TestCase): def test_weekday(self): # Test weekday directives - for directive in ('A', 'a', 'w'): + for directive in ('A', 'a', 'w', 'u'): self.helper(directive,6) def test_julian(self): @@ -458,16 +478,20 @@ class CalculationTests(unittest.TestCase): # Should be able to infer date if given year, week of year (%U or %W) # and day of the week def test_helper(ymd_tuple, test_reason): - for directive in ('W', 'U'): - format_string = "%%Y %%%s %%w" % directive - dt_date = datetime_date(*ymd_tuple) - strp_input = dt_date.strftime(format_string) - strp_output = _strptime._strptime_time(strp_input, format_string) - self.assertTrue(strp_output[:3] == ymd_tuple, - "%s(%s) test failed w/ '%s': %s != %s (%s != %s)" % - (test_reason, directive, strp_input, - strp_output[:3], ymd_tuple, - strp_output[7], dt_date.timetuple()[7])) + for year_week_format in ('%Y %W', '%Y %U', '%G %V'): + for weekday_format in ('%w', '%u', '%a', '%A'): + format_string = year_week_format + ' ' + weekday_format + with self.subTest(test_reason, + date=ymd_tuple, + format=format_string): + dt_date = datetime_date(*ymd_tuple) + strp_input = dt_date.strftime(format_string) + strp_output = _strptime._strptime_time(strp_input, + format_string) + msg = "%r: %s != %s" % (strp_input, + strp_output[7], + dt_date.timetuple()[7]) + self.assertEqual(strp_output[:3], ymd_tuple, msg) test_helper((1901, 1, 3), "week 0") test_helper((1901, 1, 8), "common case") test_helper((1901, 1, 13), "day on Sunday") @@ -499,18 +523,25 @@ class CalculationTests(unittest.TestCase): self.assertEqual(_strptime._strptime_time(value, format)[:-1], expected) check('2015 0 0', '%Y %U %w', 2014, 12, 28, 0, 0, 0, 6, -3) check('2015 0 0', '%Y %W %w', 2015, 1, 4, 0, 0, 0, 6, 4) + check('2015 1 1', '%G %V %u', 2014, 12, 29, 0, 0, 0, 0, 363) check('2015 0 1', '%Y %U %w', 2014, 12, 29, 0, 0, 0, 0, -2) check('2015 0 1', '%Y %W %w', 2014, 12, 29, 0, 0, 0, 0, -2) + check('2015 1 2', '%G %V %u', 2014, 12, 30, 0, 0, 0, 1, 364) check('2015 0 2', '%Y %U %w', 2014, 12, 30, 0, 0, 0, 1, -1) check('2015 0 2', '%Y %W %w', 2014, 12, 30, 0, 0, 0, 1, -1) + check('2015 1 3', '%G %V %u', 2014, 12, 31, 0, 0, 0, 2, 365) check('2015 0 3', '%Y %U %w', 2014, 12, 31, 0, 0, 0, 2, 0) check('2015 0 3', '%Y %W %w', 2014, 12, 31, 0, 0, 0, 2, 0) + check('2015 1 4', '%G %V %u', 2015, 1, 1, 0, 0, 0, 3, 1) check('2015 0 4', '%Y %U %w', 2015, 1, 1, 0, 0, 0, 3, 1) check('2015 0 4', '%Y %W %w', 2015, 1, 1, 0, 0, 0, 3, 1) + check('2015 1 5', '%G %V %u', 2015, 1, 2, 0, 0, 0, 4, 2) check('2015 0 5', '%Y %U %w', 2015, 1, 2, 0, 0, 0, 4, 2) check('2015 0 5', '%Y %W %w', 2015, 1, 2, 0, 0, 0, 4, 2) + check('2015 1 6', '%G %V %u', 2015, 1, 3, 0, 0, 0, 5, 3) check('2015 0 6', '%Y %U %w', 2015, 1, 3, 0, 0, 0, 5, 3) check('2015 0 6', '%Y %W %w', 2015, 1, 3, 0, 0, 0, 5, 3) + check('2015 1 7', '%G %V %u', 2015, 1, 4, 0, 0, 0, 6, 4) class CacheTests(unittest.TestCase): @@ -383,6 +383,9 @@ Library - Issue #23572: Fixed functools.singledispatch on classes with falsy metaclasses. Patch by Ethan Furman. +- Issue #12006: Add ISO 8601 year, week, and day directives (%G, %V, %u) to + strptime. + Documentation ------------- |