Small modification to enable usage by external scripts (#956)

* Make training code usable by external scripts

Add parameter inputs to training and argument parsing function to allow this script to be used by an external call.

* Apply suggestions from code review
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

examples/dreambooth/train_dreambooth.py

@@ -26,7 +26,7 @@ from transformers import CLIPTextModel, CLIPTokenizer
 logger = get_logger(__name__)
 
 
-def parse_args():
+def parse_args(input_args):
     parser = argparse.ArgumentParser(description="Simple example of a training script.")
     parser.add_argument(
         "--pretrained_model_name_or_path",
@@ -196,7 +196,11 @@ def parse_args():
     )
     parser.add_argument("--local_rank", type=int, default=-1, help="For distributed training: local_rank")
 
-    args = parser.parse_args()
+    if input_args is not None:
+        args = parser.parse_args(input_args)
+    else:
+        args = parser.parse_args()
+
     env_local_rank = int(os.environ.get("LOCAL_RANK", -1))
     if env_local_rank != -1 and env_local_rank != args.local_rank:
         args.local_rank = env_local_rank
@@ -319,8 +323,7 @@ def get_full_repo_name(model_id: str, organization: Optional[str] = None, token:
         return f"{organization}/{model_id}"
 
 
-def main():
-    args = parse_args()
+def main(args):
     logging_dir = Path(args.output_dir, args.logging_dir)
 
     accelerator = Accelerator(
@@ -653,4 +656,5 @@ def main():
 
 
 if __name__ == "__main__":
-    main()
+    args = parse_args()
+    main(args)