Fixes in CIFAR dataset format (cvat-ai#243)

* Add folder creation

* Update changelog

CHANGELOG.md

@@ -10,7 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Support for escaping in attribiute values in LabelMe format (<https://github.com/openvinotoolkit/datumaro/issues/49>)
 - Support for Segmentation Splitting (<https://github.com/openvinotoolkit/datumaro/pull/223>)
-- Support for CIFAR-10/100 dataset format (<https://github.com/openvinotoolkit/datumaro/pull/225>)
+- Support for CIFAR-10/100 dataset format (<https://github.com/openvinotoolkit/datumaro/pull/225>, <https://github.com/openvinotoolkit/datumaro/pull/243>)
 - Support COCO panoptic and stuff format (<https://github.com/openvinotoolkit/datumaro/pull/210>)
 - Documentation file and integration tests for Pascal VOC format (<https://github.com/openvinotoolkit/datumaro/pull/228>)
 - Support for MNIST and MNIST in CSV dataset formats (<https://github.com/openvinotoolkit/datumaro/pull/234>)

datumaro/plugins/cifar_format.py

@@ -2,6 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
+import os
 import os.path as osp
 import pickle
 
@@ -117,8 +118,9 @@ class CifarConverter(Converter):
     DEFAULT_IMAGE_EXT = '.png'
 
     def apply(self):
-        label_categories = self._extractor.categories()[AnnotationType.label]
+        os.makedirs(self._save_dir, exist_ok=True)
 
+        label_categories = self._extractor.categories()[AnnotationType.label]
         label_names = []
         for label in label_categories:
             label_names.append(label.name)