[Question]: How to set a default prompt tempalte for a model? about llama_index HOT 2 CLOSED

from llama_index.core.prompts.base import SelectorPromptTemplate, PromptTemplate
from llama_index.core.prompts.utils import is_chat_model

# Define your custom PromptTemplate
custom_prompt_template = PromptTemplate(template="Your custom prompt template here")

# Define conditionals if any (e.g., for chat models)
custom_conditionals = [(is_chat_model, custom_prompt_template)]

# Create a SelectorPromptTemplate with your custom prompt and conditionals
CUSTOM_PROMPT_SEL = SelectorPromptTemplate(
    default_template=custom_prompt_template,
    conditionals=custom_conditionals,
)

# Now, `CUSTOM_PROMPT_SEL` is set as the default wrapper for the model

def completion_to_prompt(completion):
  system_prompt = "..."
  return f"""<|begin_of_text|><|start_header_id|>system<|end_header_id|>

{system_prompt}<|eot_id|><|start_header_id|>user<|end_header_id|>

{completion}<|eot_id|><|start_header_id|>assistant<|end_header_id|>"""


# this is very naive, I know llama3 has a chat format, I'm not typing out the logic 
# normally you'd use message.role and message.content to build a prompt
def messages_to_prompt(messages):
  prompt_str = "\n".join([str(x) for x in messages])
  return completion_to_prompt(prompt_str)
  
llm = OpenAILike(..., messages_to_prompt=messages_to_prompt, completion_to_prompt=completion_to_prompt)