Generate a release schedule as an .ics file

pep_sphinx_extensions/pep_zero_generator/pep_index_generator.py

@@ -26,7 +26,7 @@
 from pep_sphinx_extensions.pep_zero_generator import subindices
 from pep_sphinx_extensions.pep_zero_generator import writer
 from pep_sphinx_extensions.pep_zero_generator.constants import SUBINDICES_BY_TOPIC
-from release_management.serialize import create_release_cycle, create_release_json
+from release_management.serialize import create_release_cycle, create_release_schedule_calendar, create_release_json
 
 if TYPE_CHECKING:
     from sphinx.application import Sphinx
@@ -79,3 +79,6 @@ def create_pep_zero(app: Sphinx, env: BuildEnvironment, docnames: list[str]) ->
 
     release_json = create_release_json()
     app.outdir.joinpath('api/python-releases.json').write_text(release_json, encoding="utf-8")
+
+    release_ical = create_release_schedule_calendar()
+    app.outdir.joinpath('release-schedule.ics').write_text(release_ical, encoding="utf-8")

pytest.ini

@@ -5,12 +5,12 @@ addopts =
     --strict-config
     --strict-markers
     --import-mode=importlib
-    --cov check_peps --cov pep_sphinx_extensions
+    --cov check_peps --cov pep_sphinx_extensions --cov release_management
     --cov-report html --cov-report xml
 empty_parameter_set_mark = fail_at_collect
 filterwarnings =
     error
 minversion = 6.0
-testpaths = pep_sphinx_extensions
+testpaths = pep_sphinx_extensions release_management
 xfail_strict = True
 disable_test_id_escaping_and_forfeit_all_rights_to_community_support = True

release_management/__init__.py

@@ -23,6 +23,7 @@
 RELEASE_DIR = Path(__file__).resolve().parent
 ROOT_DIR = RELEASE_DIR.parent
 PEP_ROOT = ROOT_DIR / 'peps'
+_PYTHON_RELEASES = None
 
 dc_kw = {'kw_only': True, 'slots': True} if sys.version_info[:2] >= (3, 10) else {}
 
@@ -68,6 +69,10 @@ def schedule_bullet(self):
 
 
 def load_python_releases() -> PythonReleases:
+    global _PYTHON_RELEASES
+    if _PYTHON_RELEASES is not None:
+        return _PYTHON_RELEASES
+
     with open(RELEASE_DIR / 'python-releases.toml', 'rb') as f:
         python_releases = tomllib.load(f)
     all_metadata = {
@@ -78,4 +83,5 @@ def load_python_releases() -> PythonReleases:
         v: [ReleaseInfo(**r) for r in releases]
         for v, releases in python_releases['release'].items()
     }
-    return PythonReleases(metadata=all_metadata, releases=all_releases)
+    _PYTHON_RELEASES = PythonReleases(metadata=all_metadata, releases=all_releases)
+    return _PYTHON_RELEASES

release_management/__main__.py

@@ -6,6 +6,7 @@
     CMD_FULL_JSON := 'full-json',
     CMD_UPDATE_PEPS := 'update-peps',
     CMD_RELEASE_CYCLE := 'release-cycle',
+    CMD_CALENDAR := 'calendar',
 )
 parser = argparse.ArgumentParser(allow_abbrev=False)
 parser.add_argument('COMMAND', choices=commands)
@@ -31,3 +32,11 @@
     json_path = ROOT_DIR / 'release-cycle.json'
     json_path.write_text(create_release_cycle(), encoding='utf-8')
     raise SystemExit(0)
+
+if args.COMMAND == CMD_CALENDAR:
+    from release_management import ROOT_DIR
+    from release_management.serialize import create_release_schedule_calendar
+
+    calendar_path = ROOT_DIR / 'release-schedule.ics'
+    calendar_path.write_text(create_release_schedule_calendar(), encoding='utf-8')
+    raise SystemExit(0)

release_management/serialize.py

@@ -1,13 +1,26 @@
 from __future__ import annotations
 
+import datetime as dt
 import dataclasses
 import json
 
 from release_management import ROOT_DIR, load_python_releases
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
-    from release_management import VersionMetadata
+    from release_management import ReleaseInfo, VersionMetadata
+
+# Seven years captures the full lifecycle from prereleases to end-of-life
+TODAY = dt.date.today()
+SEVEN_YEARS_AGO = TODAY.replace(year=TODAY.year - 7)
+
+# https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.11
+CALENDAR_ESCAPE_TEXT = str.maketrans({
+    '\\': r'\\',
+    ';': r'\;',
+    ',': r'\,',
+    '\n': r'\n',
+})
 
 
 def create_release_json() -> str:
@@ -48,3 +61,52 @@ def version_info(metadata: VersionMetadata, /) -> dict[str, str | int]:
         'end_of_life': end_of_life,
         'release_manager': metadata.release_manager,
     }
+
+
+def create_release_schedule_calendar() -> str:
+    python_releases = load_python_releases()
+    releases = []
+    for version, all_releases in python_releases.releases.items():
+        pep_number = python_releases.metadata[version].pep
+        for release in all_releases:
+            # Keep size reasonable by omitting releases older than 7 years
+            if release.date < SEVEN_YEARS_AGO:
+                continue
+            releases.append((pep_number, release))
+    releases.sort(key=lambda r: r[1].date)
+    lines = release_schedule_calendar_lines(releases)
+    return '\r\n'.join(lines)
+
+
+def release_schedule_calendar_lines(
+    releases: list[tuple[int, ReleaseInfo]], /
+) -> list[str]:
+    lines = [
+        'BEGIN:VCALENDAR',
+        'VERSION:2.0',
+        'PRODID:-//Python Software Foundation//Python release schedule//EN',
+        'X-WR-CALDESC:Python releases schedule from https://peps.python.org',
+        'X-WR-CALNAME:Python releases schedule',
+    ]
+    for pep_number, release in releases:
+        normalised_stage = release.stage.casefold().replace(' ', '')
+        normalised_stage = normalised_stage.translate(CALENDAR_ESCAPE_TEXT)
+        if release.note:
+            normalised_note = release.note.translate(CALENDAR_ESCAPE_TEXT)
+            note = (f'DESCRIPTION:Note: {normalised_note}',)
+        else:
+            note = ()
+        lines += (
+            'BEGIN:VEVENT',
+            f'SUMMARY:Python {release.stage}',
+            f'DTSTART;VALUE=DATE:{release.date.strftime("%Y%m%d")}',
+            f'UID:python-{normalised_stage}@releases.python.org',
+            *note,
+            f'URL:https://peps.python.org/pep-{pep_number:04d}/',
+            'END:VEVENT',
+        )
+    lines += (
+        'END:VCALENDAR',
+        '',
+    )
+    return lines

release_management/tests/test_release_schedule_calendar.py

@@ -0,0 +1,47 @@
+import datetime as dt
+
+from release_management import ReleaseInfo, serialize
+
+FAKE_RELEASE = ReleaseInfo(
+    stage='X.Y.Z final',
+    state='actual',
+    date=dt.date(2000, 1, 1),
+    note='These characters need escaping: \\ , ; \n',
+)
+
+
+def test_create_release_calendar_has_calendar_metadata() -> None:
+    # Act
+    cal_lines = serialize.create_release_schedule_calendar().split('\r\n')
+
+    # Assert
+
+    # Check calendar metadata
+    assert cal_lines[:5] == [
+        'BEGIN:VCALENDAR',
+        'VERSION:2.0',
+        'PRODID:-//Python Software Foundation//Python release schedule//EN',
+        'X-WR-CALDESC:Python releases schedule from https://peps.python.org',
+        'X-WR-CALNAME:Python releases schedule',
+    ]
+    assert cal_lines[-2:] == [
+        'END:VCALENDAR',
+        '',
+    ]
+
+
+def test_create_release_calendar_first_event() -> None:
+    # Act
+    releases = [(9999, FAKE_RELEASE)]
+    cal_lines = serialize.release_schedule_calendar_lines(releases)
+
+    # Assert
+    assert cal_lines[5] == 'BEGIN:VEVENT'
+    assert cal_lines[6] == 'SUMMARY:Python X.Y.Z final'
+    assert cal_lines[7] == 'DTSTART;VALUE=DATE:20000101'
+    assert cal_lines[8] == 'UID:python-x.y.zfinal@releases.python.org'
+    assert cal_lines[9] == (
+        'DESCRIPTION:Note: These characters need escaping: \\\\ \\, \\; \\n'
+    )
+    assert cal_lines[10] == 'URL:https://peps.python.org/pep-9999/'
+    assert cal_lines[11] == 'END:VEVENT'