Add Qwen example (#134)

* Add qwen model draft

* Add readme and requirements for qwen example

* Add model and tokenizer options

* Fix convert and tokenizer

* some updates / style consistency

* move to llm subdir

* readme nit

---------

Co-authored-by: Awni Hannun <awni@apple.com>

llms/qwen/convert.py

@@ -0,0 +1,42 @@
+import argparse
+from transformers import AutoModelForCausalLM
+import numpy as np
+import torch
+import json
+
+
+def replace_key(key: str) -> str:
+    if key.startswith("transformer."):
+        # remove transformer prefix
+        key = key.replace("transformer.", "")
+
+    return key
+
+
+def convert(model_path: str = "Qwen/Qwen-1_8B"):
+    model = AutoModelForCausalLM.from_pretrained(
+        model_path, trust_remote_code=True, torch_dtype=torch.float16
+    )
+    state_dict = model.state_dict()
+    weights = {replace_key(k): v.numpy() for k, v in state_dict.items()}
+    np.savez("weights.npz", **weights)
+
+    # write config
+    config = model.config
+    config_dict = config.to_dict()
+    with open("config.json", "w") as f:
+        json.dump(config_dict, f, indent=4)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Convert Qwen model to npz")
+
+    parser.add_argument(
+        "--model",
+        help="The huggingface model to be converted",
+        default="Qwen/Qwen-1_8B",
+    )
+
+    args = parser.parse_args()
+
+    convert(args.model)