refactor!: simplify --output to always mean directory

Remove -O/-o short flags and the output_file parameter. The --output
option now only accepts a directory path; passing a .json file path
prints an error and exits. This removes the fragile file/directory
heuristic and the special save-and-close behavior.

Author: wkentaro

README.md

@@ -97,7 +97,7 @@ labelme  # just open gui
 # tutorial (single image example)
 cd examples/tutorial
 labelme apc2016_obj3.jpg  # specify image file
-labelme apc2016_obj3.jpg -O apc2016_obj3.json  # close window after the save
+labelme apc2016_obj3.jpg --output annotations/  # save annotation JSON files to a directory
 labelme apc2016_obj3.jpg --nodata  # not include image data but relative image path in JSON file
 labelme apc2016_obj3.jpg \
   --labels highland_6539_self_stick_notes,mead_index_cards,kong_air_dog_squeakair_tennis_ball  # specify label list

labelme/__main__.py

@@ -111,10 +111,7 @@ def main():
     parser.add_argument("filename", nargs="?", help="image or label filename")
     parser.add_argument(
         "--output",
-        "-O",
-        "-o",
-        help="output file or directory (if it ends with .json it is "
-        "recognized as file, else as directory)",
+        help="output directory for saving annotation JSON files",
     )
     default_config_file = get_user_config_file()
     parser.add_argument(
@@ -237,13 +234,14 @@ def main():
     del config_str
     config_overrides.update(config_from_args)
 
-    output_file = None
     output_dir = None
     if output is not None:
         if output.endswith(".json"):
-            output_file = output
-        else:
-            output_dir = output
+            parser.error(
+                f"--output expects a directory path, but '{output}' looks like a file."
+                " Remove the .json extension or provide a directory path."
+            )
+        output_dir = output
 
     translator = QtCore.QTranslator()
     translator.load(
@@ -261,7 +259,6 @@ def main():
         config_file=config_file,
         config_overrides=config_overrides,
         filename=filename,
-        output_file=output_file,
         output_dir=output_dir,
     )
 

labelme/app.py

@@ -109,16 +109,8 @@ def __init__(
         config_file: Path | None = None,
         config_overrides: dict | None = None,
         filename: str | None = None,
-        output: str | None = None,
-        output_file: str | None = None,
         output_dir: str | None = None,
     ) -> None:
-        if output is not None:
-            logger.warning("argument output is deprecated, use output_file instead")
-            if output_file is None:
-                output_file = output
-        del output
-
         super().__init__()
         self.setWindowTitle(__appname__)
 
@@ -917,13 +909,6 @@ def __init__(
         self.statusBar().addWidget(self.status_right, 0)
         self.statusBar().show()
 
-        if output_file is not None and self._config["auto_save"]:
-            logger.warning(
-                "If `auto_save` argument is True, `output_file` argument "
-                "is ignored and output filename is automatically "
-                "set as IMAGE_BASENAME.json."
-            )
-        self.output_file = output_file
         self.output_dir = output_dir
 
         # Application state.
@@ -2067,11 +2052,7 @@ def changeOutputDirDialog(self, _value=False):
     def saveFile(self, _value=False):
         assert not self.image.isNull(), "cannot save empty image"
         if self.labelFile:
-            # DL20180323 - overwrite when in directory
             self._saveFile(self.labelFile.filename)
-        elif self.output_file:
-            self._saveFile(self.output_file)
-            self.close()
         else:
             self._saveFile(self.saveFileDialog())
 

tests/e2e/annotation_test.py

@@ -26,7 +26,8 @@ def test_MainWindow_annotate_jpg(
 
     win: labelme.app.MainWindow = labelme.app.MainWindow(
         filename=input_file,
-        output_file=out_file,
+        config_overrides=dict(auto_save=True),
+        output_dir=str(tmp_path),
     )
     qtbot.addWidget(win)
     show_window_and_wait_for_imagedata(qtbot=qtbot, win=win)