Fix save_path bug in textual inversion training script (#4710)

* Update textual_inversion.py

fixed safe_path bug in textual inversion training

* Update test_examples.py

update test_textual_inversion for updating saved file's name

* Update textual_inversion.py

fixed some formatting issues

---------
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

examples/test_examples.py

@@ -122,7 +122,7 @@ class ExamplesTestsAccelerate(unittest.TestCase):
 
             run_command(self._launch_args + test_args)
             # save_pretrained smoke test
-            self.assertTrue(os.path.isfile(os.path.join(tmpdir, "learned_embeds.bin")))
+            self.assertTrue(os.path.isfile(os.path.join(tmpdir, "learned_embeds.safetensors")))
 
     def test_dreambooth(self):
         with tempfile.TemporaryDirectory() as tmpdir:

examples/textual_inversion/textual_inversion.py

@@ -887,7 +887,12 @@ def main():
                 progress_bar.update(1)
                 global_step += 1
                 if global_step % args.save_steps == 0:
-                    save_path = os.path.join(args.output_dir, f"learned_embeds-steps-{global_step}.bin")
+                    weight_name = (
+                        f"learned_embeds-steps-{global_step}.bin"
+                        if args.no_safe_serialization 
+                        else f"learned_embeds-steps-{global_step}.safetensors"
+                    )
+                    save_path = os.path.join(args.output_dir, weight_name)
                     save_progress(
                         text_encoder,
                         placeholder_token_ids,
@@ -952,7 +957,8 @@ def main():
             )
             pipeline.save_pretrained(args.output_dir)
         # Save the newly trained embeddings
-        save_path = os.path.join(args.output_dir, "learned_embeds.bin")
+        weight_name = "learned_embeds.bin" if args.no_safe_serialization else "learned_embeds.safetensors"
+        save_path = os.path.join(args.output_dir, weight_name)
         save_progress(
             text_encoder,
             placeholder_token_ids,