autotag: accept files from stdin with '-'.

Fix `autotag` so you can pass a filename of '-' to read a file from
stdin. This way you can do this:

  docker run --rm -i ghcr.io/danbooru/autotagger autotag - < image.jpg

...to perform prediction on a single file outside of Docker.

autotag

@@ -7,19 +7,20 @@ from autotagger import Autotagger
 from pathlib import Path
 from more_itertools import ichunked
 
-@click.command(help="Automatically generate tags for an image.", context_settings=dict(max_content_width=140))
+@click.command(help="Automatically generate tags for a list of images.", context_settings=dict(max_content_width=140))
 @click.option("-t", "--threshold", default=0.01, type=float, show_default=True, help="The minimum tag confidence level.")
 @click.option("-n", "--limit", default=50, type=int, show_default=True, help="The maximum number of tags to return per image.")
 @click.option("-b", "--batch", "bs", default=128, type=int, show_default=True, help="The number of images to process per batch.")
 @click.option("--group-tags/--flatten-tags", default=True, show_default=True, help="Output rows in {filename, tags} format or {filename, tag, score} format.")
 @click.option("-m", "--model", default="models/model.pth", type=click.Path(exists=True), show_default=True, help="The model to use.")
-@click.argument("file", nargs=-1, type=click.Path(exists=True, allow_dash=True), required=True)
-def main(file, threshold, limit, bs, group_tags, model):
+@click.argument("files", nargs=-1, type=click.Path(exists=True, allow_dash=True, path_type=Path), required=True)
+def main(files, threshold, limit, bs, group_tags, model):
     autotagger = Autotagger(model)
 
-    for filepaths in ichunked(get_filepaths(file), bs):
+    for filepaths in ichunked(get_filepaths(files), bs):
         filepaths = list(filepaths)
-        predictions = autotagger.predict(filepaths, threshold=threshold, limit=limit, bs=bs)
+        files = [click.open_file(filepath, "rb") for filepath in filepaths]
+        predictions = autotagger.predict(files, threshold=threshold, limit=limit, bs=bs)
 
         for filepath, tags in zip(filepaths, predictions):
             if group_tags:
@@ -31,11 +32,11 @@ def main(file, threshold, limit, bs, group_tags, model):
                     click.echo(json.dumps(data))
 
 def get_filepaths(paths):
-    files = (recurse_dir(p) if Path(p).is_dir() else iter([p]) for p in paths)
+    files = (recurse_dir(path) if path.is_dir() else iter([path]) for path in paths)
     return itertools.chain(*files)
 
 def recurse_dir(directory):
-    return (path for path in Path(directory).glob("**/*") if not path.is_dir())
+    return (path for path in directory.glob("**/*") if not path.is_dir())
 
 if __name__ == "__main__":
     main()