https://github.com/python/cpython/commit/438cbd857a875efc105b4215b1ae131e67af37e1
commit: 438cbd857a875efc105b4215b1ae131e67af37e1
branch: main
author: Dzmitry Plashchynski <plashchyn...@gmail.com>
committer: encukou <encu...@gmail.com>
date: 2025-07-31T14:06:33+02:00
summary:
gh-131146: Fix month names in a "standalone form" in calendar module (GH-131147)
The calendar module displays month names in some locales using the genitive
case.
This is grammatically incorrect, as the nominative case should be used when the
month
is named by itself. To address this issue, this change introduces new lists
`standalone_month_name` and `standalone_month_abbr` that contain month names in
the nominative case -- or more generally, in the form that should be used to
name the month itself, rather than form a date.
The module now uses the `%OB` format specifier to get month names in this form
where available.
files:
A Misc/NEWS.d/next/Library/2025-03-17-21-21-06.gh-issue-131146.A5Obgv.rst
M Doc/library/calendar.rst
M Lib/calendar.py
M Lib/test/test_calendar.py
diff --git a/Doc/library/calendar.rst b/Doc/library/calendar.rst
index b292d828841f2f..fd397547a04437 100644
--- a/Doc/library/calendar.rst
+++ b/Doc/library/calendar.rst
@@ -501,6 +501,14 @@ The :mod:`calendar` module exports the following data
attributes:
>>> list(calendar.month_name)
['', 'January', 'February', 'March', 'April', 'May', 'June', 'July',
'August', 'September', 'October', 'November', 'December']
+ .. caution::
+
+ In locales with alternative month names forms, the :data:`!month_name`
sequence
+ may not be suitable when a month name stands by itself and not as part
of a date.
+ For instance, in Greek and in many Slavic and Baltic languages,
:data:`!month_name`
+ will produce the month in genitive case. Use
:data:`standalone_month_name` for a form
+ suitable for standalone use.
+
.. data:: month_abbr
@@ -512,6 +520,31 @@ The :mod:`calendar` module exports the following data
attributes:
>>> list(calendar.month_abbr)
['', 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep',
'Oct', 'Nov', 'Dec']
+ .. caution::
+
+ In locales with alternative month names forms, the :data:`!month_abbr`
sequence
+ may not be suitable when a month name stands by itself and not as part
of a date.
+ Use :data:`standalone_month_abbr` for a form suitable for standalone use.
+
+
+.. data:: standalone_month_name
+
+ A sequence that represents the months of the year in the current locale
+ in the standalone form if the locale provides one. Else it is equivalent
+ to :data:`month_name`.
+
+ .. versionadded:: next
+
+
+.. data:: standalone_month_abbr
+
+ A sequence that represents the abbreviated months of the year in the current
+ locale in the standalone form if the locale provides one. Else it is
+ equivalent to :data:`month_abbr`.
+
+ .. versionadded:: next
+
+
.. data:: JANUARY
FEBRUARY
MARCH
diff --git a/Lib/calendar.py b/Lib/calendar.py
index 3be1b50500eb07..45bb265a65602c 100644
--- a/Lib/calendar.py
+++ b/Lib/calendar.py
@@ -14,8 +14,9 @@
__all__ = ["IllegalMonthError", "IllegalWeekdayError", "setfirstweekday",
"firstweekday", "isleap", "leapdays", "weekday", "monthrange",
"monthcalendar", "prmonth", "month", "prcal", "calendar",
- "timegm", "month_name", "month_abbr", "day_name", "day_abbr",
- "Calendar", "TextCalendar", "HTMLCalendar", "LocaleTextCalendar",
+ "timegm", "month_name", "month_abbr", "standalone_month_name",
+ "standalone_month_abbr", "day_name", "day_abbr", "Calendar",
+ "TextCalendar", "HTMLCalendar", "LocaleTextCalendar",
"LocaleHTMLCalendar", "weekheader",
"Day", "Month", "JANUARY", "FEBRUARY", "MARCH",
"APRIL", "MAY", "JUNE", "JULY",
@@ -139,6 +140,16 @@ def __len__(self):
month_name = _localized_month('%B')
month_abbr = _localized_month('%b')
+# On platforms that support the %OB and %Ob specifiers, they are used
+# to get the standalone form of the month name. This is required for
+# some languages such as Greek, Slavic, and Baltic languages.
+try:
+ standalone_month_name = _localized_month('%OB')
+ standalone_month_abbr = _localized_month('%Ob')
+except ValueError:
+ standalone_month_name = month_name
+ standalone_month_abbr = month_abbr
+
def isleap(year):
"""Return True for leap years, False for non-leap years."""
@@ -377,7 +388,7 @@ def formatmonthname(self, theyear, themonth, width,
withyear=True):
"""
_validate_month(themonth)
- s = month_name[themonth]
+ s = standalone_month_name[themonth]
if withyear:
s = "%s %r" % (s, theyear)
return s.center(width)
@@ -510,9 +521,9 @@ def formatmonthname(self, theyear, themonth, withyear=True):
"""
_validate_month(themonth)
if withyear:
- s = '%s %s' % (month_name[themonth], theyear)
+ s = '%s %s' % (standalone_month_name[themonth], theyear)
else:
- s = '%s' % month_name[themonth]
+ s = standalone_month_name[themonth]
return '<tr><th colspan="7" class="%s">%s</th></tr>' % (
self.cssclass_month_head, s)
diff --git a/Lib/test/test_calendar.py b/Lib/test/test_calendar.py
index bc39c86b8cf62d..589a21baf7bd61 100644
--- a/Lib/test/test_calendar.py
+++ b/Lib/test/test_calendar.py
@@ -8,6 +8,7 @@
import io
import locale
import os
+import platform
import sys
import time
@@ -546,7 +547,8 @@ def test_days(self):
self.assertEqual(value[::-1], list(reversed(value)))
def test_months(self):
- for attr in "month_name", "month_abbr":
+ for attr in ("month_name", "month_abbr", "standalone_month_name",
+ "standalone_month_abbr"):
value = getattr(calendar, attr)
self.assertEqual(len(value), 13)
self.assertEqual(len(value[:]), 13)
@@ -556,6 +558,38 @@ def test_months(self):
# verify it "acts like a sequence" in two forms of iteration
self.assertEqual(value[::-1], list(reversed(value)))
+ @support.run_with_locale('LC_ALL', 'pl_PL')
+ @unittest.skipUnless(sys.platform == 'darwin' or platform.libc_ver()[0] ==
'glibc',
+ "Guaranteed to work with glibc and macOS")
+ def test_standalone_month_name_and_abbr_pl_locale(self):
+ expected_standalone_month_names = [
+ "", "styczeń", "luty", "marzec", "kwiecień", "maj", "czerwiec",
+ "lipiec", "sierpień", "wrzesień", "październik", "listopad",
+ "grudzień"
+ ]
+ expected_standalone_month_abbr = [
+ "", "sty", "lut", "mar", "kwi", "maj", "cze",
+ "lip", "sie", "wrz", "paź", "lis", "gru"
+ ]
+ self.assertEqual(
+ list(calendar.standalone_month_name),
+ expected_standalone_month_names
+ )
+ self.assertEqual(
+ list(calendar.standalone_month_abbr),
+ expected_standalone_month_abbr
+ )
+
+ def test_standalone_month_name_and_abbr_C_locale(self):
+ # Ensure that the standalone month names and abbreviations are
+ # equal to the regular month names and abbreviations for
+ # the "C" locale.
+ with calendar.different_locale("C"):
+ self.assertListEqual(list(calendar.month_name),
+ list(calendar.standalone_month_name))
+ self.assertListEqual(list(calendar.month_abbr),
+ list(calendar.standalone_month_abbr))
+
def test_locale_text_calendar(self):
try:
cal = calendar.LocaleTextCalendar(locale='')
diff --git
a/Misc/NEWS.d/next/Library/2025-03-17-21-21-06.gh-issue-131146.A5Obgv.rst
b/Misc/NEWS.d/next/Library/2025-03-17-21-21-06.gh-issue-131146.A5Obgv.rst
new file mode 100644
index 00000000000000..6d8bc0959aed52
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-03-17-21-21-06.gh-issue-131146.A5Obgv.rst
@@ -0,0 +1,6 @@
+Fix :class:`calendar.TextCalendar`, :class:`calendar.HTMLCalendar`,
+and the :mod:`calendar` CLI to display month names in the nominative
+case by adding :data:`calendar.standalone_month_name` and
+:data:`calendar.standalone_month_abbr`, which provide month names and
+abbreviations in the grammatical form used when a month name stands by
+itself, if the locale supports it.
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