Object-oriented prompt engineering for LLMs
Stop wrestling with string templates. Build composable, testable, and maintainable prompts using object-oriented design patterns.
# Instead of this messy string concatenation...
prompt = f"""
Analyze this data:
{open('data.csv').read()}
Using these functions:
{str(my_functions)}
"""
# Write clean, composable prompts like this:
from proompt import CsvDataProvider, FileDataProvider, PromptSection, ToolContext
# MySection is illustrative β define `class MySection(PromptSection)` with your own
# `render()` (see "Prompt Sections - Compose Complex Prompts" below for a concrete example)
section = MySection(
context=my_context,
providers=[CsvDataProvider("data.csv"), FileDataProvider("file.txt")],
tools=[ToolContext(my_function)],
)Proompt is organized into a clean, modular structure:
proompt/
βββ src/proompt/
β βββ base/ # Abstract base classes
β β βββ context.py
β β βββ mixins.py
β β βββ prompt.py
β β βββ provider.py
β βββ providers/ # Concrete data provider implementations
β βββ __init__.py # Re-exports the concrete providers
β βββ data.py # Provider implementations and tabular helpers
βββ examples/ # Complete usage examples
β βββ 01-simple_quarterly_review.py
β βββ 02-intermediate_quarterly_review.py
β βββ 03-advanced_quarterly_review.py
β βββ 04-pydantic_ai_tools_integration.py
βββ tests/ # Unit tests
Key Components:
- Base classes define contracts for providers, contexts, and prompts
- Data providers concrete examples of how to extend
BaseProvider - Examples show real-world implementations from simple to advanced
- Tests ensure reliability and demonstrate usage patterns
All of the above is available from the top-level proompt package
(from proompt import ...); concrete providers are also importable from the shorter
proompt.providers path, e.g. from proompt.providers import CsvDataProvider, SqliteProvider.
Traditional string-based prompts are painful:
- π₯ Hard to compose and maintain large prompts
- π No separation between data and prompt logic
- π« Difficult to test individual components
- π Can't reuse prompt components across projects
β οΈ No type safety or validation
Proompt solves this with:
- β Composable objects - Build prompts from reusable components
- β Data providers - Clean separation of data sources and prompt logic
- β Type safety - Abstract base classes enforce contracts
- β Testable - Unit test each component independently
- β Extensible - Easy to create custom providers and contexts
- β Async ready - Support for both sync and async operations
uv pip install proomptfrom proompt import FileDataProvider
# Read a file and inject it into your prompt
provider = FileDataProvider("data.txt")
content = provider.run() # Returns file contents as string
print(f"Analyze the data:\n{content}")A few example classes for extending the BaseProvider class can be found in the proompt.providers module.
Providers fetch data from external sources and format it for LLM consumption:
from proompt import CsvDataProvider, SqliteProvider
# CSV data as TableData; call .to_md() for a markdown table
csv_provider = CsvDataProvider("sales_data.csv")
print(csv_provider.run().to_md())
# | Product | Sales | Region |
# | --- | --- | --- |
# | Widget | 1000 | North |
# Database queries as TableData; call .to_md() for a markdown table
db_provider = SqliteProvider(
"company.db",
'SELECT * FROM employees WHERE department = "Engineering"'
)
print(db_provider.run().to_md())
# | name | role | salary |
# | --- | --- | --- |
# | Alice | Developer | 85000 |Note: to_md() output is intentionally unpadded (single-dash --- separators, no
column-width alignment) β the tables above show the exact output, not a prettified version.
Automatically generate function documentation that LLMs can understand:
from proompt import ToolContext
def calculate_tax(income: float, rate: float = 0.25) -> float:
"""Calculate tax owed on income."""
return income * rate
tool_ctx = ToolContext(calculate_tax)
print(tool_ctx.render())
# render() starts and ends with a blank line:
#
# Name: calculate_tax
# Description: Calculate tax owed on income.
# Arguments: income: float, rate: float = 0.25
# Returns: float
# Usage: Reference description for usage.
#Combine providers, tools, and context into reusable sections:
from textwrap import dedent
from proompt import Context, CsvDataProvider, PromptSection, ToolContext
class MyContext(Context):
"""Trivial Context example β holds and renders arbitrary dynamic info."""
def __init__(self, data: str):
self.data = data
def render(self) -> str:
return self.data
def calculate_tax(income: float, rate: float = 0.25) -> float:
"""Calculate tax owed on income."""
return income * rate
class DataAnalysisSection(PromptSection):
def formatter(self, instruction: str) -> str:
data = "\n\n".join(p.run().to_md() for p in self.providers)
tools = "\n\n".join(str(t) for t in self.tools)
return dedent(f"""
{instruction}
Available Data Providers:
{data}
Available Tools:
{tools}
""")
def render(self) -> str:
return self.formatter("Analyze the provided data")
# Use it
context = MyContext("Q3 2024 sales review")
section = DataAnalysisSection(
context=context, # Use Context to pass dynamic info
providers=[CsvDataProvider("metrics.csv")], # accepts any number of Providers
tools=[ToolContext(calculate_tax)],
)
prompt = str(section) # Ready for your LLMfrom proompt import FileDataProvider
# Read any text file
provider = FileDataProvider("config.yaml")
content = provider.run() # raw string contentNOTE: for structured YAML parsing, extend BaseProvider to create a YamlProvider class
from proompt import CsvDataProvider
# Returns raw TableData; call .to_md() to format
provider = CsvDataProvider("data.csv")
table = provider.run() # TableData instance
markdown = table.to_md() # Formatted markdown tableSee proompt.providers.TableData and proompt.providers.to_markdown_table() for conversion.
import asyncio
from proompt import SqliteProvider
# Execute SQL queries, get raw TableData back
provider = SqliteProvider(
database_path="app.db",
query="SELECT name, email FROM users WHERE active = 1",
table_name="users" # Optional, for better context
)
# Async support; NOTE the async only runs sync method .run()
async def main() -> None:
result = await provider.arun() # TableData instance
markdown = result.to_md() # Formatted markdown table
print(markdown)
asyncio.run(main())NOTE: A true asynchronous method would need to be defined when extending the BaseProvider class.
Creating custom providers is straightforward:
import json
from urllib.request import Request, urlopen
from proompt import BaseProvider
class ApiProvider(BaseProvider[dict]):
def __init__(self, url: str, api_key: str):
self.url = url
self.api_key = api_key
@property
def name(self) -> str:
return f"API Provider for {self.url}"
@property
def provider_ctx(self) -> str:
return f"Fetches data from REST API at {self.url}"
# NOTE: would be useful to include available endpoints
def run(self, endpoint: str) -> dict:
request = Request(
f"{self.url}/{endpoint}",
headers={"Authorization": f"Bearer {self.api_key}"}
)
with urlopen(request) as response:
return json.load(response)
# Use your custom provider
api = ApiProvider("https://api.example.com", "your-key")
data = api.run("users")Convert any data format to LLM-friendly markdown:
from proompt import TableData
# From dictionaries
data = [
{"name": "Alice", "role": "Engineer", "salary": 85000},
{"name": "Bob", "role": "Designer", "salary": 75000}
]
table = TableData.from_dicts(data)
markdown = table.to_md()
print(markdown)
# | name | role | salary |
# | --- | --- | --- |
# | Alice | Engineer | 85000 |
# | Bob | Designer | 75000 |BaseProvider- Abstract base for all data providersContext- Abstract base for prompt contextsToolContext- Documents functions for LLM consumptionPromptSection- Composable prompt sectionsBasePrompt- Full prompt composition
Importable from the top-level proompt package or from proompt.providers
(from proompt.providers import CsvDataProvider, SqliteProvider, FileDataProvider, ...):
FileDataProvider- Read text filesCsvDataProvider- Read CSV files asTableData(.to_md()for markdown)SqliteProvider- Execute SQL queries, returnsTableData(.to_md()for markdown)
TableData- Convert various formats to markdown tablesto_markdown_table()- Low-level table formatting
Better Organization
# Instead of managing giant prompt strings
SYSTEM_PROMPT = """You are an assistant..."""
DATA_SECTION = """Here is the data: {data}"""
TOOL_SECTION = """Available tools: {tools}"""
# Compose from organized, testable objects
prompt = ChatPrompt(
SystemSection("You are an assistant..."),
DataSection(providers=[csv_provider, db_provider]),
ToolSection(tools=[calculator, parser])
)Easier Testing
# Test individual components
def test_csv_provider():
provider = CsvDataProvider("test.csv")
result = provider.run().to_md()
assert "| Name |" in result
def test_tool_context():
ctx = ToolContext(my_function)
assert "my_function" in ctx.render()Reusable Components
# Define once, use everywhere
analysis_section = DataAnalysisSection(
providers=[CsvDataProvider("metrics.csv")]
)
# Reuse in different prompts
customer_prompt = CustomerPrompt(analysis_section, ...)
admin_prompt = AdminPrompt(analysis_section, ...)Coming soon