Development

Software Development Guide

Overview

This skill provides best practices, code snippets, and workflows for modern software development. Use it whenever you need help writing or organizing code, setting up environments, or debugging.

Key Principles

• Modular design: Break functionality into small, reusable modules. Use descriptive function and variable names.
• Version control: Use Git to track changes. Commit early and often with meaningful messages.
• Documentation: Write docstrings and comments. Include a README.md in your projects.

Python Development

Setting up a project

# Create virtual environment
python3 -m venv .venv
source .venv/bin/activate

# Install dependencies
pip install -r requirements.txt

# Format code with black and check style
pip install black isort flake8
black src/
isort src/
flake8 src/

Creating a CLI application

import argparse


def main():
    parser = argparse.ArgumentParser(description="Example CLI")
    parser.add_argument("input_file", help="Path to input file")
    args = parser.parse_args()

    with open(args.input_file) as f:
        content = f.read()
    print(content)


if __name__ == "__main__":
    main()

Debugging with pdb

import pdb


def divide(a, b):
    pdb.set_trace()
    return a / b

Run your script with python -m pdb script.py to step through execution.

JavaScript/Node.js Development

Initializing a project

npm init -y
npm install express

Creating an Express server

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World!');
});

app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

Debugging

Use node --inspect-brk to debug your code with Chrome DevTools. Add breakpoints or use debugger; statements in your script.

Best Practices

• Write unit tests before implementing features (see the testing skill).
• Structure code into packages and modules.
• Use continuous integration (CI) to automatically run tests and linters.
• Document important APIs in a docs folder or inline with docstrings.

Additional Resources

• Python Packaging Authority’s packaging guide.
• Node.js documentation.
• Atlassian Git tutorials.