llama-cpp-python Usage

2min
Every Functionary model release comes with GGUF file formats . Thus, Functionary can be loaded and used in a much wider variety of hardware using llama.cpp. Currently, we provide the following quantization:
4-bit
8-bit
FP16 (except for functionary-medium-v2.* due to file size)
Setup
Make sure that llama-cpp-python is successully installed in your system. The following is the sample code:
Python
from llama_cpp import Llama
from functionary.prompt_template import get_prompt_template_from_tokenizer
from transformers import AutoTokenizer

tools = [ # For functionary-7b-v2 we use "tools"; for functionary-7b-v1.4 we use "functions" = [{"name": "get_current_weather", "description":..., "parameters": ....}]
    {
        "type": "function",
        "function": {
            "name": "get_current_weather",
            "description": "Get the current weather",
            "parameters": {
                "type": "object",
                "properties": {
                    "location": {
                        "type": "string",
                        "description": "The city and state, e.g., San Francisco, CA"
                    }
                },
                "required": ["location"]
            }
        }
    }
]


# You can download gguf files from https://huggingface.co/meetkai/functionary-7b-v2-GGUF/tree/main
llm = Llama(model_path="PATH_TO_GGUF_FILE", n_ctx=4096, n_gpu_layers=-1)
messages = [
    {"role": "user", "content": "what's the weather like in Hanoi?"}
]

# Create tokenizer from HF. 
# We found that the tokenizer from llama_cpp is not compatible with tokenizer from HF that we trained
# The reason might be we added new tokens to the original tokenizer
# So we will use tokenizer from HuggingFace
tokenizer = AutoTokenizer.from_pretrained("meetkai/functionary-7b-v2", legacy=True)
# prompt_template will be used for creating the prompt
prompt_template = get_prompt_template_from_tokenizer(tokenizer)

# Before inference, we need to add an empty assistant (message without content or function_call)
messages.append({"role": "assistant"})

# Create the prompt to use for inference
prompt_str = prompt_template.get_prompt_from_messages(messages, tools)
token_ids = tokenizer.encode(prompt_str)

gen_tokens = []
# Get list of stop_tokens 
stop_token_ids = [tokenizer.encode(token)[-1] for token in prompt_template.get_stop_tokens_for_generation()]
print("stop_token_ids: ", stop_token_ids)

# We use function generate (instead of __call__) so we can pass in list of token_ids
for token_id in llm.generate(token_ids, temp=0):
    if token_id in stop_token_ids:
        break
    gen_tokens.append(token_id)

llm_output = tokenizer.decode(gen_tokens)

# parse the message from llm_output
result = prompt_template.parse_assistant_response(llm_output)
print(result)
from llama_cpp import Llama
from functionary.prompt_template import get_prompt_template_from_tokenizer
from transformers import AutoTokenizer

tools = [ # For functionary-7b-v2 we use "tools"; for functionary-7b-v1.4 we use "functions" = [{"name": "get_current_weather", "description":..., "parameters": ....}]
    {
        "type": "function",
        "function": {
            "name": "get_current_weather",
            "description": "Get the current weather",
            "parameters": {
                "type": "object",
                "properties": {
                    "location": {
                        "type": "string",
                        "description": "The city and state, e.g., San Francisco, CA"
                    }
                },
                "required": ["location"]
            }
        }
    }
]


# You can download gguf files from https://huggingface.co/meetkai/functionary-7b-v2-GGUF/tree/main
llm = Llama(model_path="PATH_TO_GGUF_FILE", n_ctx=4096, n_gpu_layers=-1)
messages = [
    {"role": "user", "content": "what's the weather like in Hanoi?"}
]

# Create tokenizer from HF. 
# We found that the tokenizer from llama_cpp is not compatible with tokenizer from HF that we trained
# The reason might be we added new tokens to the original tokenizer
# So we will use tokenizer from HuggingFace
tokenizer = AutoTokenizer.from_pretrained("meetkai/functionary-7b-v2", legacy=True)
# prompt_template will be used for creating the prompt
prompt_template = get_prompt_template_from_tokenizer(tokenizer)

# Before inference, we need to add an empty assistant (message without content or function_call)
messages.append({"role": "assistant"})

# Create the prompt to use for inference
prompt_str = prompt_template.get_prompt_from_messages(messages, tools)
token_ids = tokenizer.encode(prompt_str)

gen_tokens = []
# Get list of stop_tokens 
stop_token_ids = [tokenizer.encode(token)[-1] for token in prompt_template.get_stop_tokens_for_generation()]
print("stop_token_ids: ", stop_token_ids)

# We use function generate (instead of __call__) so we can pass in list of token_ids
for token_id in llm.generate(token_ids, temp=0):
    if token_id in stop_token_ids:
        break
    gen_tokens.append(token_id)

llm_output = tokenizer.decode(gen_tokens)

# parse the message from llm_output
result = prompt_template.parse_assistant_response(llm_output)
print(result)
﻿
The output would be:
Python
{'role': 'assistant', 'content': None, 'tool_calls': [{'type': 'function', 'function': {'name': 'get_current_weather', 'arguments': '{\n  "location": "Hanoi"\n}'}}]}
{'role': 'assistant', 'content': None, 'tool_calls': [{'type': 'function', 'function': {'name': 'get_current_weather', 'arguments': '{\n  "location": "Hanoi"\n}'}}]}
﻿
Note: we should use the tokenizer from Huggingface to convert prompt into token_ids instead of using the tokenizer from LLama_cpp because we found that tokenizer from LLama_cpp doesn't give the same result as that from Huggingface. The reason might be in the training, we added new tokens to the tokenizer and LLama_Cpp doesn't handle this succesfully
Updated 25 Mar 2024
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