Add script to update download buttons

.github/scripts/update-download-buttons.py

@@ -0,0 +1,57 @@
+import os, pathlib, re, sys, subprocess
+
+CWD = os.path.dirname(__file__)
+ROOT_DIR = os.path.dirname(os.path.dirname(CWD))
+SENTINEL_BEGIN = "DL_BUTTONS_BEGIN"
+SENTINEL_END = "DL_BUTTONS_END"
+
+
+def latest_git_tag_version() -> str:
+    p = subprocess.run(
+        ["git", "describe", "--tags", "--abbrev=0"],
+        cwd=ROOT_DIR,
+        capture_output=True,
+        text=True,
+    )
+    if p.returncode != 0:
+        raise RuntimeError("failed to get latest git tag")
+    tag = str(p.stdout).strip()
+    if not re.search(r"^v\d+\.\d+\.\d+$", tag):
+        raise RuntimeError(f"bad tag format: {tag}")
+    return tag[1:]
+
+
+def update_download_buttons(file: pathlib.Path, version: str):
+    with open(file, "rt") as f:
+        replace = False
+        has_replaced = False
+        new_lines = []
+        for line in f.readlines():
+            new_lines.append(line)
+            if SENTINEL_BEGIN in line:
+                replace = True
+                continue
+            if SENTINEL_END in line:
+                replace = False
+                continue
+            if replace:
+                line_new, n = re.subn(r"\d+\.\d+\.\d+", version, line)
+                if n > 0:
+                    has_replaced = True
+                    new_lines.pop()
+                    new_lines.append(line_new)
+    if has_replaced:
+        new_content = "".join(new_lines)
+        with open(file, "wt") as f:
+            f.write(new_content)
+        pure_path = pathlib.PurePosixPath(file.relative_to(ROOT_DIR))
+        print(f"Updated {pure_path} to version {version}")
+
+
+if __name__ == "__main__":
+    version = latest_git_tag_version()
+    for file in [
+        pathlib.Path(os.path.join(ROOT_DIR, "README.md")),
+        *pathlib.Path(os.path.join(ROOT_DIR, "documentation")).rglob("*.md"),
+    ]:
+        update_download_buttons(file, version)