replace assert with exception in src/transformers/utils/model_pararallel_utils.py (#14072)

* replace assert with exception in src/transformers/utils/model_parallel_utils.py

* fix some code style

* fix typo
Co-authored-by: skpig <1900012999@pku.edu.cn>

src/transformers/utils/model_parallel_utils.py

@@ -30,19 +30,21 @@ def assert_device_map(device_map, num_blocks):
     missing_blocks = [i for i in blocks if i not in device_map_blocks]
     extra_blocks = [i for i in device_map_blocks if i not in blocks]
 
-    assert len(duplicate_blocks) == 0, (
-        "Duplicate attention blocks specified in device_map. Attention blocks must be specified to one device. These "
-        "attention blocks were specified more than once: " + str(duplicate_blocks)
-    )
-    assert len(missing_blocks) == 0, (
-        "There are attention blocks for this model that are not specified in the device_map. Add these attention "
-        "blocks to a device on the device_map: " + str(missing_blocks)
-    )
-    assert (
-        len(extra_blocks) == 0
-    ), "The device_map contains more attention blocks than this model has. Remove these from the device_map:" + str(
-        extra_blocks
-    )
+    if len(duplicate_blocks) != 0:
+        raise ValueError(
+            "Duplicate attention blocks specified in device_map. Attention blocks must be specified to one device. These "
+            "attention blocks were specified more than once: " + str(duplicate_blocks)
+        )
+    if len(missing_blocks) != 0:
+        raise ValueError(
+            "There are attention blocks for this model that are not specified in the device_map. Add these attention "
+            "blocks to a device on the device_map: " + str(missing_blocks)
+        )
+    if len(extra_blocks) != 0:
+        raise ValueError(
+            "The device_map contains more attention blocks than this model has. Remove these from the device_map:"
+            + str(extra_blocks)
+        )
 
 
 def get_device_map(n_layers, devices):