Advanced Prompt Techniques (Variable Mappings, Functions)¶
In this notebook we show some advanced prompt techniques. These features allow you to define more custom/expressive prompts, re-use existing ones, and also express certain operations in fewer lines of code.
We show the following features:
- Partial formatting
- Prompt template variable mappings
- Prompt function mappings
%pip install llama-index-llms-openai
from llama_index.core import PromptTemplate
from llama_index.llms.openai import OpenAI
1. Partial Formatting¶
Partial formatting (partial_format
) allows you to partially format a prompt, filling in some variables while leaving others to be filled in later.
This is a nice convenience function so you don't have to maintain all the required prompt variables all the way down to format
, you can partially format as they come in.
This will create a copy of the prompt template.
qa_prompt_tmpl_str = """\
Context information is below.
---------------------
{context_str}
---------------------
Given the context information and not prior knowledge, answer the query.
Please write the answer in the style of {tone_name}
Query: {query_str}
Answer: \
"""
prompt_tmpl = PromptTemplate(qa_prompt_tmpl_str)
partial_prompt_tmpl = prompt_tmpl.partial_format(tone_name="Shakespeare")
partial_prompt_tmpl.kwargs
{'tone_name': 'Shakespeare'}
fmt_prompt = partial_prompt_tmpl.format(
context_str="In this work, we develop and release Llama 2, a collection of pretrained and fine-tuned large language models (LLMs) ranging in scale from 7 billion to 70 billion parameters",
query_str="How many params does llama 2 have",
)
print(fmt_prompt)
Context information is below. --------------------- In this work, we develop and release Llama 2, a collection of pretrained and fine-tuned large language models (LLMs) ranging in scale from 7 billion to 70 billion parameters --------------------- Given the context information and not prior knowledge, answer the query. Please write the answer in the style of Shakespeare Query: How many params does llama 2 have Answer:
2. Prompt Template Variable Mappings¶
Template var mappings allow you to specify a mapping from the "expected" prompt keys (e.g. context_str
and query_str
for response synthesis), with the keys actually in your template.
This allows you re-use your existing string templates without having to annoyingly change out the template variables.
# NOTE: here notice we use `my_context` and `my_query` as template variables
qa_prompt_tmpl_str = """\
Context information is below.
---------------------
{my_context}
---------------------
Given the context information and not prior knowledge, answer the query.
Query: {my_query}
Answer: \
"""
template_var_mappings = {"context_str": "my_context", "query_str": "my_query"}
prompt_tmpl = PromptTemplate(
qa_prompt_tmpl_str, template_var_mappings=template_var_mappings
)
fmt_prompt = partial_prompt_tmpl.format(
context_str="In this work, we develop and release Llama 2, a collection of pretrained and fine-tuned large language models (LLMs) ranging in scale from 7 billion to 70 billion parameters",
query_str="How many params does llama 2 have",
)
print(fmt_prompt)
Context information is below. --------------------- In this work, we develop and release Llama 2, a collection of pretrained and fine-tuned large language models (LLMs) ranging in scale from 7 billion to 70 billion parameters --------------------- Given the context information and not prior knowledge, answer the query. Please write the answer in the style of Shakespeare Query: How many params does llama 2 have Answer:
3. Prompt Function Mappings¶
You can also pass in functions as template variables instead of fixed values.
This allows you to dynamically inject certain values, dependent on other values, during query-time.
Here are some basic examples. We show more advanced examples (e.g. few-shot examples) in our Prompt Engineering for RAG guide.
qa_prompt_tmpl_str = """\
Context information is below.
---------------------
{context_str}
---------------------
Given the context information and not prior knowledge, answer the query.
Query: {query_str}
Answer: \
"""
def format_context_fn(**kwargs):
# format context with bullet points
context_list = kwargs["context_str"].split("\n\n")
fmtted_context = "\n\n".join([f"- {c}" for c in context_list])
return fmtted_context
prompt_tmpl = PromptTemplate(
qa_prompt_tmpl_str, function_mappings={"context_str": format_context_fn}
)
context_str = """\
In this work, we develop and release Llama 2, a collection of pretrained and fine-tuned large language models (LLMs) ranging in scale from 7 billion to 70 billion parameters.
Our fine-tuned LLMs, called Llama 2-Chat, are optimized for dialogue use cases.
Our models outperform open-source chat models on most benchmarks we tested, and based on our human evaluations for helpfulness and safety, may be a suitable substitute for closed-source models.
"""
fmt_prompt = prompt_tmpl.format(
context_str=context_str, query_str="How many params does llama 2 have"
)
print(fmt_prompt)
Context information is below. --------------------- - In this work, we develop and release Llama 2, a collection of pretrained and fine-tuned large language models (LLMs) ranging in scale from 7 billion to 70 billion parameters. - Our fine-tuned LLMs, called Llama 2-Chat, are optimized for dialogue use cases. - Our models outperform open-source chat models on most benchmarks we tested, and based on our human evaluations for helpfulness and safety, may be a suitable substitute for closed-source models. --------------------- Given the context information and not prior knowledge, answer the query. Query: How many params does llama 2 have Answer: