# Clean Code Principles

> Use when applying clean code and software craftsmanship.

- Skill: `loopyluci/clean-code-principles` (Agent Skill)
- Install (CLI): `npx skillmds@latest add loopyluci/clean-code-principles`
- Raw SKILL.md: https://api.skillmd.com/api/skills/loopyluci/clean-code-principles/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: LoopyLuci (https://skillmd.com/u/loopyluci)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/loopyluci/clean-code-principles

---


# Clean Code Principles

Writing clean, maintainable, and readable code — from naming conventions and function design through SOLID principles, comments, and code organization.

## When to Use

- Writing new code that will be maintained by others
- Reviewing code for readability and maintainability
- Refactoring legacy code to be more understandable
- Onboarding new developers to code standards
- Improving code quality across a team

## Core Principles

```python
# Principle 1: Meaningful Names
# BAD:
def fn(a, b):
    x = a + b
    return x * 0.1

# GOOD:
def calculate_tax(income: float, tax_rate: float) -> float:
    taxable_income = income
    tax_amount = taxable_income * tax_rate
    return tax_amount

# Principle 2: Small Functions (do one thing)
# BAD:
def process_order(order):
    validate(order)
    total = sum(item['price'] for item in order['items'])
    if total > 100: total *= 0.9  # Discount logic mixed in
    charge_payment(order['customer'], total)
    send_email(order['customer']['email'], f"Order confirmed for ${total}")
    update_inventory(order['items'])

# GOOD:
def process_order(order):
    validate_order(order)
    total = calculate_order_total(order)
    charge_customer(order['customer'], total)
    send_confirmation(order['customer'], total)
    update_inventory(order['items'])
```

## Verification Checklist

- [ ] Names reveal intent (not `data`, `info`, `temp`, `x`)
- [ ] Functions do one thing (3-5 lines ideal)
- [ ] No side effects (functions only do what they say)
- [ ] Comments explain WHY not WHAT
- [ ] Error handling is separate from business logic
- [ ] Tests exist before or alongside code