Add ability to load_dataset without a template for simpler usage for …

…beginners (#1350)

* Add ability to run without template for simpler api

Signed-off-by: elronbandel <elronbandel@gmail.com>

* Fix to be more genral

Signed-off-by: elronbandel <elronbandel@gmail.com>

* Fix

Signed-off-by: elronbandel <elronbandel@gmail.com>

---------

Signed-off-by: elronbandel <elronbandel@gmail.com>

src/unitxt/standard.py

@@ -145,7 +145,7 @@ def verify(self):
 
         if self.template is None:
             raise ValueError(
-                "You must set in the recipe either `template`, `template_card_index` or `templates`."
+                "You must set in the recipe either `template`, `template_card_index`."
             )
 
         if isinstance(self.template, list):
@@ -411,9 +411,22 @@ def prepare(self):
         assert (
             self.template_card_index is None or self.template is None
         ), f"Specify either template ({self.template}) or template_card_index ({self.template_card_index}) but not both"
-        assert not (
-            self.template_card_index is None and self.template is None
-        ), "Specify either template or template_card_index in card"
+
+        if self.template_card_index is None and self.template is None:
+            if self.card is not None:
+                self.template_card_index = (
+                    0
+                    if isinstance(self.card.templates, list)
+                    else next(iter(self.card.templates.keys()))
+                )
+                logger.warning(
+                    "Template was not specified in recipe, using the first template from the card by default."
+                )
+            else:
+                raise ValueError(
+                    "Specify a template or template_card_index, or a card to get a default template from."
+                )
+
         if self.template_card_index is not None:
             try:
                 self.template = self.card.templates[self.template_card_index]

tests/library/test_api.py

@@ -13,6 +13,12 @@
 class TestAPI(UnitxtTestCase):
     maxDiff = None
 
+    def test_load_dataset_without_template(self):
+        dataset = load_dataset(
+            "card=cards.stsb",
+        )
+        self.assertEqual(len(dataset["train"]), 282)
+
     def test_load_dataset(self):
         dataset = load_dataset(
             "card=cards.stsb,template=templates.regression.two_texts.simple,max_train_instances=5,max_validation_instances=5,max_test_instances=5",

tests/library/test_recipe.py

@@ -554,13 +554,6 @@ def test_standard_recipe_with_no_test(self):
         self.assertTrue(len(results) > 0)
 
     def test_standard_recipe_with_template_errors(self):
-        # Check some template was specified
-        with self.assertRaises(AssertionError) as cm:
-            StandardRecipeWithIndexes(card="cards.wnli")
-        self.assertEqual(
-            str(cm.exception), "Specify either template or template_card_index in card"
-        )
-
         # Check either template or template index was specified , but not both
         with self.assertRaises(AssertionError) as cm:
             StandardRecipeWithIndexes(