refactor: run checker as python -m check_meta

README.md

@@ -127,20 +127,22 @@ used the instrument (one name or several). `permission.date` is when that
 share was granted.
 
 ```bash
-python templates/check_meta.py ./gold-512-bin4
+python -m check_meta ./gold-512-bin4
 hf upload bobleesj/quantem-data ./gold-512-bin4 \
   widget-tutorials/show4dstem/gold-512-bin4/full \
   --repo-type dataset --create-pr
 ```
 
-The last path is the folder on this repo. `./gold-512-bin4` is your local
-folder (`data.npy` + `meta.json`). The hub path is
+Run `python -m check_meta` from a checkout of this dataset so the
+`check_meta/` package is importable. `./gold-512-bin4` is your local
+folder (`data.npy` + `meta.json`). The last `hf upload` path is the
+folder on this repo. The hub path is
 `widget-tutorials/<widget>/<name>/<size>/`. For a new ShowBragg set that
 would be `widget-tutorials/showbragg/<name>/full`. Size is `small`,
 `medium`, `large`, or `full`. Use `widget-tutorials/shared/` only when
 more than one widget will read the same files.
 
-`check_meta.py` must print `ok` or do not open the PR. Resume a stopped
+`python -m check_meta` must print `ok` or do not open the PR. Resume a stopped
 upload with `--revision refs/pr/N` (do not pass `--create-pr` again).
 Merge is on the
 [Community tab](https://huggingface.co/datasets/bobleesj/quantem-data/discussions).
@@ -180,5 +182,5 @@ yourself. Put that receipt in `meta.json` (`permission.received`,
 `permission.from`, `permission.collectors`, `permission.date`). If you
 collected it yourself, set `from` and `collectors` to your name.
 
-Do not open a pull request without that permission. `check_meta.py` must
-print `ok`.
+Do not open a pull request without that permission. `python -m check_meta`
+must print `ok`.

templates/check_meta.py → check_meta/__init__.py

@@ -1,20 +1,15 @@
-#!/usr/bin/env python3
 """Refuse a folder whose meta.json is missing required keys.
 
 Required: name, source, date, sample, shape, dtype, permission
   (permission.received, permission.from, permission.collectors,
   permission.date). from and collectors are one or more names.
 Optional: sampling, units, and optics keys.
-
-Usage:
-    python check_meta.py /path/to/folder
 """
 
 from __future__ import annotations
 
 import json
 import re
-import sys
 from pathlib import Path
 
 REQUIRED = ("name", "source", "date", "sample", "shape", "dtype", "permission")
@@ -22,7 +17,7 @@ PERMISSION_REQUIRED = ("received", "from", "collectors", "date")
 DATE_RE = re.compile(r"^\d{4}-\d{2}-\d{2}$")
 
 
-def _name_list(value) -> list[str] | None:
+def _name_list(value: object) -> list[str] | None:
     """Accept one name or a list of names. Empty is missing."""
 
     if isinstance(value, str) and value.strip():
@@ -40,7 +35,7 @@ def check_meta(folder: Path) -> list[str]:
     if not path.is_file():
         return [f"missing {path}"]
     try:
-        meta = json.loads(path.read_text())
+        meta = json.loads(path.read_text(encoding="utf-8"))
     except json.JSONDecodeError as exc:
         return [f"{path} is not JSON: {exc}"]
     if not isinstance(meta, dict):
@@ -100,25 +95,3 @@ def check_meta(folder: Path) -> list[str]:
         if isinstance(shape, list) and isinstance(units, list) and len(units) != len(shape):
             problems.append("units length must match shape length")
     return problems
-
-
-def main(argv: list[str]) -> int:
-    if len(argv) != 2:
-        print("usage: python check_meta.py /path/to/folder", file=sys.stderr)
-        return 2
-    folder = Path(argv[1])
-    if not folder.is_dir():
-        print(f"not a folder: {folder}", file=sys.stderr)
-        return 2
-    problems = check_meta(folder)
-    if problems:
-        print(f"{folder / 'meta.json'}:")
-        for item in problems:
-            print(f"  {item}")
-        return 1
-    print(f"{folder / 'meta.json'}: ok ({', '.join(REQUIRED)})")
-    return 0
-
-
-if __name__ == "__main__":
-    raise SystemExit(main(sys.argv))

check_meta/__main__.py

@@ -0,0 +1,31 @@
+"""CLI: python -m check_meta /path/to/folder"""
+
+from __future__ import annotations
+
+import argparse
+import sys
+from pathlib import Path
+
+from check_meta import REQUIRED, check_meta
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(prog="python -m check_meta")
+    parser.add_argument("folder", type=Path, help="folder that contains meta.json")
+    args = parser.parse_args(argv)
+    folder: Path = args.folder
+    if not folder.is_dir():
+        print(f"not a folder: {folder}", file=sys.stderr)
+        return 2
+    problems = check_meta(folder)
+    if problems:
+        print(f"{folder / 'meta.json'}:")
+        for item in problems:
+            print(f"  {item}")
+        return 1
+    print(f"{folder / 'meta.json'}: ok ({', '.join(REQUIRED)})")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())