--prefix option, closes #20

README.md

@@ -39,6 +39,10 @@ To process every file in the bucket with a `.pdf` extension use `--all`:
 
     s3-ocr start name-of-bucket --all
 
+To process every file with a `.pdf` extension within a specific folder, use `--prefix`:
+
+    s3-ocr start name-of-bucket --prefix path/to/folder
+
 ### s3-ocr start --help
 
 <!-- [[[cog

s3_ocr/cli.py

@@ -90,8 +90,9 @@ def cli():
 @click.argument("bucket")
 @click.argument("keys", nargs=-1)
 @click.option("--all", is_flag=True, help="Process all PDF files in the bucket")
+@click.option("--prefix", help="Process all PDF files within this prefix")
 @common_boto3_options
-def start(bucket, keys, all, **boto_options):
+def start(bucket, keys, all, prefix, **boto_options):
     """
     Start OCR tasks for PDF files in an S3 bucket
 
@@ -100,6 +101,10 @@ def start(bucket, keys, all, **boto_options):
     To process every file with a .pdf extension:
 
         s3-ocr start name-of-bucket --all
+
+    To process every .pdf in the PUBLIC/ folder:
+
+        s3-ocr start name-of-bucket --prefix PUBLIC/
     """
     s3 = make_client("s3", **boto_options)
     textract = make_client("textract", **boto_options)
@@ -114,11 +119,14 @@ def start(bucket, keys, all, **boto_options):
                 if match["Key"] in (key, key + S3_OCR_JSON):
                     items.append(match)
     else:
-        if not all:
+        if not all and not prefix:
             raise click.ClickException(
-                "Specify keys, or use --all to process all PDFs in the bucket"
+                "Specify keys, --prefix or use --all to process all PDFs in the bucket"
             )
-        items = list(paginate(s3, "list_objects_v2", "Contents", Bucket=bucket))
+        kwargs = dict(Bucket=bucket)
+        if prefix:
+            kwargs["Prefix"] = prefix
+        items = list(paginate(s3, "list_objects_v2", "Contents", **kwargs))
     # Start any item that ends in .pdf for which a .s3-ocr.json file does not exist
     keys_with_s3_ocr_files = [
         strip_ocr_json(item["Key"])

tests/test_s3_ocr.py

@@ -14,7 +14,7 @@ def test_start_with_no_options_error(s3):
         result = runner.invoke(cli, ["start", "my-bucket"])
         assert result.exit_code == 1
         assert (
-            "Specify keys, or use --all to process all PDFs in the bucket"
+            "Specify keys, --prefix or use --all to process all PDFs in the bucket"
             in result.output
         )
 
@@ -45,6 +45,23 @@ def test_start_with_specified_key(s3, textract):
     }
 
 
+def test_start_with_prefix(s3, textract):
+    s3.put_object(Bucket="my-bucket", Key="pre/blah1.pdf", Body=b"Fake PDF")
+    s3.put_object(Bucket="my-bucket", Key="pre/blah2.pdf", Body=b"Fake PDF")
+    runner = CliRunner()
+    with runner.isolated_filesystem():
+        result = runner.invoke(cli, ["start", "my-bucket", "--prefix", "pre/"])
+        assert result.exit_code == 0, result.output
+    bucket_contents = s3.list_objects_v2(Bucket="my-bucket")["Contents"]
+    assert {b["Key"] for b in bucket_contents} == {
+        "blah.pdf",
+        "pre/blah1.pdf",
+        "pre/blah1.pdf.s3-ocr.json",
+        "pre/blah2.pdf",
+        "pre/blah2.pdf.s3-ocr.json",
+    }
+
+
 @pytest.mark.parametrize(
     "files,expected",
     (