[Datumaro] Reducing nesting of tests

datumaro/datumaro/components/extractor.py

@@ -72,6 +72,20 @@ def __eq__(self, other):
 class LabelCategories(Categories):
     Category = namedtuple('Category', ['name', 'parent', 'attributes'])
 
+    @classmethod
+    def from_iterable(cls, iterable):
+        temp_categories = cls()
+
+        if isinstance(iterable, str):
+            iterable = [[iterable]]
+
+        for category in iterable:
+            if isinstance(category, str):
+                category = [category]
+            temp_categories.add(*category)
+
+        return temp_categories
+
     def __init__(self, items=None, attributes=None):
         super().__init__(attributes=attributes)
 
@@ -482,6 +496,19 @@ def iou(self, other):
 class PointsCategories(Categories):
     Category = namedtuple('Category', ['labels', 'joints'])
 
+    @classmethod
+    def from_iterable(cls, iterable):
+        temp_categories = cls()
+
+        if isinstance(iterable, int):
+            iterable = [[iterable]]
+
+        for category in iterable:
+            if isinstance(category, int):
+                category = [category]
+            temp_categories.add(*category)
+        return temp_categories
+
     def __init__(self, items=None, attributes=None):
         super().__init__(attributes=attributes)
 

datumaro/datumaro/components/project.py

@@ -18,7 +18,7 @@
 from datumaro.components.config import Config, DEFAULT_FORMAT
 from datumaro.components.config_model import (Model, Source,
     PROJECT_DEFAULT_CONFIG, PROJECT_SCHEMA)
-from datumaro.components.extractor import Extractor
+from datumaro.components.extractor import Extractor, LabelCategories
 from datumaro.components.launcher import ModelTransform
 from datumaro.components.dataset_filter import \
     XPathDatasetFilter, XPathAnnotationsFilter
@@ -315,6 +315,33 @@ def categories(self):
         return self._parent.categories()
 
 class Dataset(Extractor):
+    @classmethod
+    def from_iterable(cls, iterable, categories=None):
+        """Generation of Dataset from iterable object
+
+        Args:
+            iterable: Iterable object contains DatasetItems
+            categories (dict, optional): Dict of categories of datasets. Defaults to {}.
+
+        Returns:
+            Dataset: Dataset object
+        """
+
+        if isinstance(categories, list):
+            categories = LabelCategories.from_iterable(categories)
+
+        if not categories:
+            categories = {}
+
+        class tmpExtractor(Extractor):
+            def __iter__(self):
+                return iter(iterable)
+
+            def categories(self):
+                return categories
+
+        return cls.from_extractors(tmpExtractor())
+
     @classmethod
     def from_extractors(cls, *sources):
         # merge categories