Generate a release schedule as an .ics file

.pre-commit-config.yaml

@@ -71,11 +71,12 @@ repos:
           - '--check'
         files: '^release_management/'
 
-  - repo: https://github.com/tox-dev/tox-ini-fmt
-    rev: 1.4.1
-    hooks:
-      - id: tox-ini-fmt
-        name: "Format tox.ini"
+#  Disabled: no support for comments as at 2025-11-27.
+#  - repo: https://github.com/tox-dev/tox-ini-fmt
+#    rev: 1.4.1
+#    hooks:
+#      - id: tox-ini-fmt
+#        name: "Format tox.ini"
 
   - repo: https://github.com/sphinx-contrib/sphinx-lint
     rev: v1.0.0

.pytest.toml

@@ -12,6 +12,7 @@ addopts = [
     # https://pytest-cov.readthedocs.io/en/latest/config.html#reference
     "--cov=check_peps",
     "--cov=pep_sphinx_extensions",
+    "--cov=release_management",
     "--cov-report=html",
     "--cov-report=xml",
 ]
@@ -23,6 +24,7 @@ filterwarnings = ["error"]
 
 testpaths = [
     "pep_sphinx_extensions",
+    "release_management",
 ]
 
 # https://docs.pytest.org/en/stable/reference/reference.html#confval-strict

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")

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 +61,55 @@ 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]:
+    dtstamp = dt.datetime.now(dt.timezone.utc).strftime('%Y%m%dT%H%M%SZ')
+
+    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.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'DTSTAMP:{dtstamp}',
+            f'UID:python-{normalised_stage}@releases.python.org',
+            f'DTSTART;VALUE=DATE:{release.date.strftime("%Y%m%d")}',
+            f'SUMMARY:Python {release.stage}',
+            *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 +1,49 @@
+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].startswith('DTSTAMP:')
+    assert cal_lines[6].endswith('Z')
+    assert cal_lines[7] == 'UID:[email protected]'
+    assert cal_lines[8] == 'DTSTART;VALUE=DATE:20000101'
+    assert cal_lines[9] == 'SUMMARY:Python X.Y.Z final'
+    assert cal_lines[10] == (
+        'DESCRIPTION:Note: These characters need escaping: \\\\ \\, \\; \\n'
+    )
+    assert cal_lines[11] == 'URL:https://peps.python.org/pep-9999/'
+    assert cal_lines[12] == 'END:VEVENT'

tox.ini

@@ -15,8 +15,10 @@ commands =
 
 [coverage:run]
 omit =
-    */__main__.py  # Ignore all __main__.py files
-    peps/*         # Ignore all files in the PEPs folder
+    # Ignore all __main__.py files
+    */__main__.py
+    # Ignore all files in the PEPs folder
+    peps/*
 
 [coverage:report]
 exclude_also =