gguf: Add example script for extracting chat template

gguf-py/scripts/gguf-template.py

@@ -0,0 +1,103 @@
+"""
+gguf_chat_template.py - example file to extract the chat template from the models metadata
+"""
+
+from __future__ import annotations
+
+import argparse
+import logging
+import os
+import sys
+from pathlib import Path
+
+import jinja2
+
+# Necessary to load the local gguf package
+if "NO_LOCAL_GGUF" not in os.environ and (Path(__file__).parent.parent.parent / 'gguf-py').exists():
+    sys.path.insert(0, str(Path(__file__).parent.parent))
+
+from gguf.constants import Keys
+from gguf.gguf_reader import GGUFReader  # noqa: E402
+
+# Configure logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger("gguf-chat-template")
+
+
+def get_chat_template(model_file: str) -> str:
+    reader = GGUFReader(model_file)
+
+    # Available keys
+    logger.info("Detected model metadata!")
+    logger.info("Outputting available model fields:")
+    for key in reader.fields.keys():
+        logger.info(key)
+
+    # Access the 'chat_template' field directly using its key
+    chat_template_field = reader.fields.get(Keys.Tokenizer.CHAT_TEMPLATE)
+
+    if chat_template_field:
+        # Extract the chat template string from the field
+        chat_template_memmap = chat_template_field.parts[-1]
+        chat_template_string = chat_template_memmap.tobytes().decode("utf-8")
+        return chat_template_string
+    else:
+        logger.error("Chat template field not found in model metadata.")
+        return ""
+
+
+def display_chat_template(chat_template: str, format_template: bool = False):
+    """
+    Display the chat template to standard output, optionally formatting it using Jinja2.
+
+    Args:
+        chat_template (str): The extracted chat template.
+        format_template (bool, optional): Whether to format the template using Jinja2. Defaults to False.
+    """
+    logger.info(f"Format Template: {format_template}")
+
+    if format_template:
+        # Render the formatted template using Jinja2 with a context that includes 'bos_token' and 'eos_token'
+        env = jinja2.Environment(
+            loader=jinja2.BaseLoader(),
+            trim_blocks=True,
+            lstrip_blocks=True,
+        )
+        logger.info(chat_template)
+        template = env.from_string(chat_template)
+        formatted_template = template.render(
+            messages=[
+                {"role": "system", "content": "I am a helpful assistant."},
+                {"role": "user", "content": "Hello!"},
+            ],
+            bos_token="[BOS]",
+            eos_token="[EOS]",
+        )
+        print(formatted_template)
+    else:
+        # Display the raw template
+        print(chat_template)
+
+
+# Example usage:
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Extract chat template from a GGUF model file"
+    )
+    parser.add_argument("model_file", type=str, help="Path to the GGUF model file")
+    parser.add_argument(
+        "--format",
+        action="store_true",
+        help="Format the chat template using Jinja2",
+    )
+
+    args = parser.parse_args()
+
+    model_file = args.model_file
+    chat_template = get_chat_template(model_file)
+
+    display_chat_template(chat_template, format_template=args.format)
+
+
+if __name__ == "__main__":
+    main()