Python Best Practices Knowledge Base Prompt for LLMs (ChatGPT, Claude, etc.)

Boost your Python code quality instantly — without spending hours on manual refactoring!

Why This Prompt?

At the start of this year, I made a resolution to improve my Python skills by reading some of the best Python books: Fluent Python, Robust Python, High Performance Python, Python Cookbook, and Pythonic Programming. My code improved — but I still often missed key optimizations and best practices.

Manually hunting for improvements took too much time. I turned to large language models (LLMs) like ChatGPT and Claude for help — but found that although they know Python well, their code suggestions weren’t always the best:

• They’d comment every line, cluttering the code.
• Refactoring requests sometimes produced too many tiny functions that hurt readability.
• Subtle improvements like replacing lists with memory-efficient generators were often missed.

Then, Claude introduced a feature called Claude Projects to create a knowledge base by uploading files it can reference when answering. I gathered all my Python knowledge, best practices, good & bad examples, and put it into one comprehensive markdown file — a powerful knowledge base.

When you feed this file to an LLM and ask it to refactor your code, it immediately suggests better, cleaner, more Pythonic solutions.

Example

My original code:

def process_file(filename):
    with open(filename, 'r') as file:
        lines = file.readlines()

    for i in range(len(lines)):
        lines[i] = lines[i].upper()

    with open(filename, 'w') as file:
        file.writelines(lines)

process_file('your_file.txt')

How the LLM refactors it with the knowledge base in one single request:

import tempfile
import shutil
import logging
from pathlib import Path

log = logging.getLogger(__name__)


def convert_file_to_uppercase(filename: str) -> bool:
    """Convert file contents to uppercase using temporary file for safety."""
    file_path = Path(filename)
    
    try:
        with tempfile.NamedTemporaryFile(
            mode='w',
            delete=False,
            dir=file_path.parent,
            prefix=f".{file_path.name}_temp_",
            suffix=".tmp"
        ) as temp_file:
            temp_filename = temp_file.name
            
            with open(filename, 'r') as input_file:
                for line in input_file:
                    temp_file.write(line.upper())
        
        shutil.move(temp_filename, filename)
        log.info("file.converted", filename=filename)
        return True
        
    except FileNotFoundError:
        log.error("file.not_found", filename=filename)
        return False
    except PermissionError:
        log.error("file.permission_denied", filename=filename)
        return False
    except OSError as e:
        log.error("file.operation_failed", filename=filename, error=str(e))
        # Cleanup temp file if it exists
        try:
            Path(temp_filename).unlink(missing_ok=True)
        except (NameError, OSError):
            pass
        return False


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    
    success = convert_file_to_uppercase('your_file.txt')
    result_msg = "File successfully converted" if success else "Failed to process file"
    log.info("conversion.complete", success=success, message=result_msg)

Notice how the improved code includes:
✔ Better function naming
✔ Type annotations
✔ Clear docstrings
✔ File existence checks
✔ Memory-efficient processing with generators
✔ Safe file writing using temporary files
✔ Exception handling

All automatically suggested with just one prompt — saving you hours of manual optimization!

What’s Inside This Prompt?

• Comprehensive Python best practices condensed into a single knowledge base
• Common pitfalls with clear “bad vs good” code examples
• Memory and performance optimizations
• Idiomatic Python usage and style guides
• Tips on error handling, type hints, code structure, and more
• Ready to be used with Claude, ChatGPT, or other LLMs supporting knowledge base or context file uploads

How to Use

1. Claude Project
   • Create a project in Claude called Python Best Practices
   • Upload the knowledge base markdown file in the project
   • Copy-paste the system prompt from system_prompt.txt as the project/system prompt
2. ChatGPT Custom GPT (for Plus users)
   • Create a custom GPT using the ChatGPT interface
   • Add the knowledge base file and the system prompt during the setup
   • Your custom GPT will now use these to help improve your Python code
3. Direct Chat Usage
   • You can also directly upload or paste the best practices file and the system prompt in a single chat with any llm of your choice.
   • Then provide the Python code you want to improve in the same conversation
   • The model will use the knowledge base to suggest improvements

Pricing & Versions

1. Free Version
   • Covers select key topics
   • Includes code examples.
   • Ideal to get a feel for how this prompt works
2. Full Version — $2
   • Full version access

Who is this for?

• Intermediate to advanced Python developers who want to write cleaner, more efficient code
• Developers who use LLMs to aid coding and want to maximize their benefits
• Anyone looking to quickly improve Python code quality without spending hours researching or debugging

Start writing better Python code today!

Grab the free version to see how it works, then upgrade for full access and continuous updates.

If you have any questions or want help with using this prompt effectively, just reach out!