only yield existing paths

NLVR2.py

@@ -125,12 +125,13 @@ class NLVR2Dataset(datasets.GeneratorBasedBuilder):
                 right_img_identifier = f"{split_name}-{common_img_identifier[1]}-{common_img_identifier[2]}-img1.png"
                 left_image_path = str(os.path.join(images_path, left_img_identifier))
                 right_image_path = str(os.path.join(images_path, right_img_identifier))
-                record = {
-                    "identifier": ex["identifier"],
-                    "sentence": ex["sentence"],
-                    "left_image": left_image_path,
-                    "right_image": right_image_path,
-                    "label": ex["label"],
-                }
-                idx += 1
-                yield idx, record
+                if os.path.exists(left_image_path) and os.path.exists(right_image_path):
+                    record = {
+                        "identifier": ex["identifier"],
+                        "sentence": ex["sentence"],
+                        "left_image": left_image_path,
+                        "right_image": right_image_path,
+                        "label": ex["label"],
+                    }
+                    idx += 1
+                    yield idx, record