Game version in the menu: VERSION holds vYYYYMM-NNNNN, shown on the title screen and in the pause menu, tools/bump_version.py raises it with every change

tools/bump_version.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+"""Raise the game version in VERSION: vYYYYMM-NNNNN.
+
+Run with every change to the game (the number counts the changes of the current month and
+starts again at 00001 when the month turns). The version is shown on the title screen and in
+the pause menu, and it is the version a savegame support question refers to.
+"""
+import datetime
+import pathlib
+import re
+import sys
+
+FILE = pathlib.Path(__file__).resolve().parent.parent / "VERSION"
+PATTERN = re.compile(r"^v(\d{6})-(\d{1,5})$")
+
+
+def main() -> int:
+    month = datetime.date.today().strftime("%Y%m")
+    current = FILE.read_text(encoding="utf-8").strip() if FILE.exists() else ""
+    match = PATTERN.match(current)
+    if match and match.group(1) == month:
+        number = int(match.group(2)) + 1
+    elif match:  # a new month: count again from the first change
+        number = 1
+    elif current:
+        print(f"VERSION does not look like vYYYYMM-NNNNN: {current!r}", file=sys.stderr)
+        return 1
+    else:
+        number = 1
+    version = f"v{month}-{number:05d}"
+    FILE.write_text(version + "\n", encoding="utf-8")
+    if match:
+        print(f"{current} -> {version}")
+    else:
+        print(version)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())