Fix broken external_file paths when organizing on Windows (#1832)

* Fix windows path issue

* fix tests

* use walrus operation

Author: h-mayorquin

dandi/organize.py

@@ -18,6 +18,7 @@
 from enum import Enum
 import os
 import os.path as op
+import posixpath
 from pathlib import Path, PurePosixPath
 import re
 import traceback
@@ -275,7 +276,7 @@ def _create_external_file_names(metadata: list[dict]) -> list[dict]:
             renamed_path_list = []
             uuid_str = ext_file_dict.get("id", str(uuid.uuid4()))
             for no, ext_file in enumerate(ext_file_dict["external_files"]):
-                renamed = op.join(
+                renamed = posixpath.join(
                     nwb_folder_name, f"{uuid_str}_external_file_{no}{ext_file.suffix}"
                 )
                 renamed_path_list.append(renamed)

dandi/pynwb_utils.py

@@ -17,7 +17,7 @@
 import inspect
 import os
 import os.path as op
-from pathlib import Path
+from pathlib import Path, PurePosixPath
 import re
 from typing import IO, Any, TypeVar, cast
 import warnings
@@ -408,8 +408,8 @@ def _get_image_series(nwb: pynwb.NWBFile) -> list[dict]:
             if isinstance(ob, pynwb.image.ImageSeries) and ob.external_file is not None:
                 out_dict = dict(id=ob.object_id, name=ob.name, external_files=[])
                 for ext_file in ob.external_file:
-                    if Path(ext_file).suffix in VIDEO_FILE_EXTENSIONS:
-                        out_dict["external_files"].append(Path(ext_file))
+                    if (path := PurePosixPath(ext_file)).suffix in VIDEO_FILE_EXTENSIONS:
+                        out_dict["external_files"].append(path)
                     else:
                         lgr.warning(
                             "external file %s should be one of: %s",

dandi/tests/test_organize.py

@@ -353,6 +353,10 @@ def test_video_organize(
             for ext_file_ob in ext_file_objects:
                 for no, name in enumerate(ext_file_ob["external_files"]):
                     video_files_organized.append(name)
+                    # Regression: external_file paths are DANDI/S3 keys,
+                    # must use forward slashes even on Windows.
+                    # See https://github.com/catalystneuro/nwb-video-widgets/issues/33
+                    assert "\\" not in str(name)
                     # check if external_file arguments are correctly named according to convention:
                     filename = Path(
                         f"{vid_folder.name}/{ext_file_ob['id']}_external_file_{no}"