list[Path] support

Signed-off-by: Dmitri Khokhlov <dkhokhlov@gmail.com>

python/cog/server/runner.py

@@ -382,15 +382,19 @@ def _predict(
     input_dict = initial_prediction["input"]
 
     for k, v in input_dict.items():
-        if isinstance(v, types.URLPath):
-            try:
+        try:
+            # Check if v is an instance of URLPath
+            if isinstance(v, types.URLPath):
                 input_dict[k] = v.convert()
-            except requests.exceptions.RequestException as e:
-                tb = traceback.format_exc()
-                event_handler.append_logs(tb)
-                event_handler.failed(error=str(e))
-                log.warn("failed to download url path from input", exc_info=True)
-                return event_handler.response
+            # Check if v is a list of URLPath instances
+            elif isinstance(v, list) and all(isinstance(item, types.URLPath) for item in v):
+                input_dict[k] = [item.convert() for item in v]
+        except requests.exceptions.RequestException as e:
+            tb = traceback.format_exc()
+            event_handler.append_logs(tb)
+            event_handler.failed(error=str(e))
+            log.warn("Failed to download url path from input", exc_info=True)
+            return event_handler.response
 
     for event in worker.predict(input_dict, poll=0.1):
         if should_cancel.is_set():

test-integration/test_integration/fixtures/path-list-input-project/cog.yaml

@@ -0,0 +1,3 @@
+build:
+  python_version: "3.11"
+predict: "predict.py:Predictor"

test-integration/test_integration/fixtures/path-list-input-project/predict.py

@@ -0,0 +1,9 @@
+from cog import BasePredictor, Path
+
+class Predictor(BasePredictor):
+   def predict(self, paths: list[Path]) -> str:
+       output_parts = []  # Use a list to collect file contents
+       for path in paths:
+           with open(path) as f:
+             output_parts.append(f.read())
+       return "".join(output_parts)

test-integration/test_integration/test_predict.py

@@ -229,3 +229,24 @@ def test_predict_many_inputs_with_existing_image(docker_image, tmpdir_factory):
         capture_output=True,
     )
     assert result.stdout.decode() == "hello default 20 world jpg foo 6\n"
+
+
+def test_predict_path_list_input(tmpdir_factory):
+    project_dir = Path(__file__).parent / "fixtures/path-list-input-project"
+    out_dir = pathlib.Path(tmpdir_factory.mktemp("project"))
+    shutil.copytree(project_dir, out_dir, dirs_exist_ok=True)
+    with open(out_dir / "1.txt", "w") as fh:
+        fh.write("test1")
+    with open(out_dir / "2.txt", "w") as fh:
+        fh.write("test2")
+    cmd = ["cog", "predict", "-i", "paths=[\"@1.txt\",\"@2.txt\"]"]
+
+    result = subprocess.run(
+        cmd,
+        cwd=out_dir,
+        check=True,
+        capture_output=True,
+    )
+    stdout = result.stdout.decode()
+    assert "test1" in stdout
+    assert "test2" in stdout