promptic 1.2.0

A simple yet powerful abstraction for litellm and pydantic

promptic

90% of what you need for LLM app development. Nothing you don't.

promptic is a lightweight, decorator-based Python library that simplifies the process of interacting with large language models (LLMs) using litellm. With promptic, you can effortlessly create prompts, handle input arguments, receive structured outputs from LLMs, and build agents with just a few lines of code.

Installation

pip install promptic

Usage

Basics

Functions decorated with @llm will automatically interpolate arguments into the prompt. You can also customize the model, system prompt, and more. Most arguments will be passed to litellm.completion.

from promptic import llm

@llm
def translate(text, target_language="Chinese"):
    """Translate this text: {text} 
    Target language: {target_language}"""

print(translate("Hello world!"))
# 您好，世界！

@llm(
    model="claude-3-haiku-20240307",
    system="You are a customer service analyst. Provide clear sentiment analysis with key points."
)
def analyze_sentiment(text):
    """Analyze the sentiment of this customer feedback: {text}"""

print(analyze_sentiment("The product was okay but shipping took forever"))
# Sentiment: Mixed/Negative
# Key points:
# - Neutral product satisfaction
# - Significant dissatisfaction with shipping time

Structured Outputs

You can use Pydantic models to ensure the LLM returns data in exactly the structure you expect. Simply define a Pydantic model and use it as the return type annotation on your decorated function. The LLM's response will be automatically validated against your model schema and returned as a proper Pydantic object.

from pydantic import BaseModel
from promptic import llm

class Forecast(BaseModel):
    location: str
    temperature: float
    units: str

@llm
def get_weather(location, units: str = "fahrenheit") -> Forecast:
    """What's the weather for {location} in {units}?"""

print(get_weather("San Francisco", units="celsius"))
# location='San Francisco' temperature=16.0 units='Celsius'

Agents

Functions decorated with @llm.tool become tools that the LLM can invoke to perform actions or retrieve information. The LLM will automatically execute the appropriate tool calls, creating a seamless agent interaction.

from datetime import datetime

from promptic import llm

@llm
def scheduler(command):
    """{command}"""

@scheduler.tool
def get_current_time():
    """Get the current time"""
    print("getting current time")
    return datetime.now().strftime("%I:%M %p")

@scheduler.tool
def add_reminder(task: str, time: str):
    """Add a reminder for a specific task and time"""
    print(f"adding reminder: {task} at {time}")
    return f"Reminder set: {task} at {time}"

@scheduler.tool
def check_calendar(date: str):
    """Check calendar for a specific date"""
    print(f"checking calendar for {date}")
    return f"Calendar checked for {date}: No conflicts found"

cmd = """
What time is it? 
Also, can you check my calendar for tomorrow 
and set a reminder for a team meeting at 2pm?
"""

print(scheduler(cmd))
# getting current time
# checking calendar for 2023-10-05
# adding reminder: Team meeting at 2023-10-05T14:00:00
# The current time is 3:48 PM. I checked your calendar for tomorrow, and there are no conflicts. I've also set a reminder for your team meeting at 2 PM tomorrow.

Streaming

The streaming feature allows real-time response generation, useful for long-form content or interactive applications:

from promptic import llm

@llm(stream=True)
def write_poem(topic):
    """Write a haiku about {topic}."""

print("".join(write_poem("artificial intelligence")))
# Binary thoughts hum,
# Electron minds awake, learn,
# Future thinking now.

Error Handling and Dry Runs

Dry runs allow you to see which tools will be called and their arguments without invoking the decorated tool functions. You can also enable debug mode for more detailed logging.

from promptic import llm

@llm(
    system="you are a posh smart home assistant named Jarvis",
    dry_run=True,
    debug=True,
)
def jarvis(command):
    """{command}"""

@jarvis.tool
def turn_light_on():
    """turn light on"""
    return True

@jarvis.tool
def get_current_weather(location: str, unit: str = "fahrenheit"):
    """Get the current weather in a given location"""
    return f"The weather in {location} is 45 degrees {unit}"

print(jarvis("Please turn the light on and check the weather in San Francisco"))
# ...
# [DRY RUN]: function_name = 'turn_light_on' function_args = {}
# [DRY RUN]: function_name = 'get_current_weather' function_args = {'location': 'San Francisco'}
# ...

Resilient LLM Calls with Tenacity

promptic pairs perfectly with tenacity for handling temporary API failures, rate limits, validation errors, and so on. For example, here's how you can implement a cost-effective retry strategy that starts with smaller models:

from tenacity import retry, stop_after_attempt, retry_if_exception_type
from pydantic import BaseModel, ValidationError
from promptic import llm

class MovieReview(BaseModel):
    title: str
    rating: float
    summary: str
    recommended: bool

@retry(
    # Retry only on Pydantic validation errors
    retry=retry_if_exception_type(ValidationError),
    # Try up to 3 times
    stop=stop_after_attempt(3),
)
@llm(model="gpt-3.5-turbo")  # Start with a faster, cheaper model
def analyze_movie(text) -> MovieReview:
    """Analyze this movie review and extract the key information: {text}"""

try:
    # First attempt with smaller model
    result = analyze_movie("The new Dune movie was spectacular...")
except ValidationError as e:
    # If validation fails after retries with smaller model, 
    # try one final time with a more capable model
    analyze_movie.retry.stop = stop_after_attempt(1)  # Only try once with GPT-4o
    analyze_movie.model = "gpt-4o"
    result = analyze_movie("The new Dune movie was spectacular...")

print(result)
# title='Dune' rating=9.5 summary='A spectacular sci-fi epic...' recommended=True

API Reference

llm

The main decorator for creating LLM-powered functions. Can be used as @llm or @llm() with parameters.

Parameters

• model (str, optional): The LLM model to use. Defaults to "gpt-4o-mini".
• system (str, optional): System prompt to set context for the LLM.
• dry_run (bool, optional): If True, simulates tool calls without executing them. Defaults to False.
• debug (bool, optional): If True, enables detailed logging. Defaults to False.
• **litellm_kwargs: Additional arguments passed directly to litellm.completion.

Methods

• tool(fn): Decorator method to register a function as a tool that can be called by the LLM.

Example

from promptic import llm

@llm(
    model="gpt-4",
    system="You are a helpful assistant",
    temperature=0.7
)
def generate_story(topic: str, length: str = "short"):
    """Write a {length} story about {topic}."""
    
@generate_story.tool
def get_writing_style():
    """Get the current writing style preference"""
    return "whimsical and light-hearted"

License

promptic is open-source software licensed under the Apache License 2.0.