https://github.com/python/cpython/commit/f1951900f181e3d98e1dbd191b8ab6c852d... commit: f1951900f181e3d98e1dbd191b8ab6c852d5ab8e branch: 3.11 author: Serhiy Storchaka <storchaka@gmail.com> committer: serhiy-storchaka <storchaka@gmail.com> date: 2023-12-26T20:09:41Z summary: [3.11] bpo-36959: Fix error messages for invalid ISO format string in _strptime() (GH-13408) (GH-113499) Previously some error messages complained about incompatible combinations of directives that are not contained in the format string. (cherry picked from commit 4b2c3e8e436b5191039cbe8cd9932654a60803e6) Co-authored-by: Gordon P. Hemsley <me@gphemsley.org> files: A Misc/NEWS.d/next/Library/2019-05-18-15-50-14.bpo-36959.ew6WZ4.rst M Lib/_strptime.py M Lib/test/test_strptime.py diff --git a/Lib/_strptime.py b/Lib/_strptime.py index b97dfcce1e8e4d..602059fb0e5fab 100644 --- a/Lib/_strptime.py +++ b/Lib/_strptime.py @@ -358,8 +358,6 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): tz = -1 gmtoff = None gmtoff_fraction = 0 - # Default to -1 to signify that values not known; not critical to have, - # though iso_week = week_of_year = None week_of_year_start = None # weekday and julian defaulted to None so as to signal need to calculate @@ -485,17 +483,17 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): 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 iso_year is not None: 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: + elif 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').") + elif iso_week is not None: + if year is None or 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').") @@ -505,11 +503,12 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): "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 year is None: + if month == 2 and day == 29: + year = 1904 # 1904 is first leap year of 20th century + leap_year_fix = True + else: + year = 1900 # If we know the week of the year and what day of that week, we can figure diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py index e3fcabef946116..4ea40b66592e21 100644 --- a/Lib/test/test_strptime.py +++ b/Lib/test/test_strptime.py @@ -224,25 +224,49 @@ def test_ValueError(self): 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") + msg_week_no_year_or_weekday = r"ISO week directive '%V' must be used with " \ + r"the ISO year directive '%G' and a weekday directive " \ + r"\('%A', '%a', '%w', or '%u'\)." + msg_week_not_compatible = r"ISO week directive '%V' is incompatible with " \ + r"the year directive '%Y'. Use the ISO year '%G' instead." + msg_julian_not_compatible = r"Day of the year directive '%j' is not " \ + r"compatible with ISO year directive '%G'. Use '%Y' instead." + msg_year_no_week_or_weekday = r"ISO year directive '%G' must be used with " \ + r"the ISO week directive '%V' and a weekday directive " \ + r"\('%A', '%a', '%w', or '%u'\)." + + locale_time = _strptime.LocaleTime() + # Ambiguous or incomplete cases using ISO year/week/weekday directives + subtests = [ + # 1. ISO week (%V) is specified, but the year is specified with %Y + # instead of %G + ("1999 50", "%Y %V", msg_week_no_year_or_weekday), + ("1999 50 5", "%Y %V %u", msg_week_not_compatible), + # 2. ISO year (%G) and ISO week (%V) are specified, but weekday is not + ("1999 51", "%G %V", msg_year_no_week_or_weekday), + # 3. ISO year (%G) and weekday are specified, but ISO week (%V) is not + ("1999 {}".format(locale_time.f_weekday[5]), "%G %A", + msg_year_no_week_or_weekday), + ("1999 {}".format(locale_time.a_weekday[5]), "%G %a", + msg_year_no_week_or_weekday), + ("1999 5", "%G %w", msg_year_no_week_or_weekday), + ("1999 5", "%G %u", msg_year_no_week_or_weekday), + # 4. ISO year is specified alone (e.g. time.strptime('2015', '%G')) + ("2015", "%G", msg_year_no_week_or_weekday), + # 5. Julian/ordinal day (%j) is specified with %G, but not %Y + ("1999 256", "%G %j", msg_julian_not_compatible), + ("1999 50 5 256", "%G %V %u %j", msg_julian_not_compatible), + # ISO week specified alone + ("50", "%V", msg_week_no_year_or_weekday), + # ISO year is unspecified, falling back to year + ("50 5", "%V %u", msg_week_no_year_or_weekday), + ] + + for (data_string, format, message) in subtests: + with self.subTest(data_string=data_string, format=format): + with self.assertRaisesRegex(ValueError, message): + _strptime._strptime(data_string, format) def test_strptime_exception_context(self): # check that this doesn't chain exceptions needlessly (see #17572) diff --git a/Misc/NEWS.d/next/Library/2019-05-18-15-50-14.bpo-36959.ew6WZ4.rst b/Misc/NEWS.d/next/Library/2019-05-18-15-50-14.bpo-36959.ew6WZ4.rst new file mode 100644 index 00000000000000..1ac05a730a2086 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-05-18-15-50-14.bpo-36959.ew6WZ4.rst @@ -0,0 +1,2 @@ +Fix some error messages for invalid ISO format string combinations in ``strptime()`` that referred to directives not contained in the format string. +Patch by Gordon P. Hemsley.