436-code-generation-patterns

Rules for generating maintainable code, including formatting, import order, error handling, type hints, and named constants. Type hints describe the kinds of values functions accept and return.

In plain words
What is it for?
Use them when generating or refactoring Python and similar code, especially public functions and code with error-prone logic.
Why use it?
They reduce common AI-generated code problems such as incomplete imports, hidden errors, unclear types, and hard-to-maintain formatting.

Cursor rule

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/hamzaamjad/cursor-rules/436-code-generation-patterns
Clone the repo
git clone --depth 1 https://github.com/hamzaamjad/cursor-rules
Per session 5 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 477 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00005 $0.00477
Opus 5 $0.00003 $0.00238
Sonnet 5 $0.00001 $0.00095
Haiku 4.5 $0.00001 $0.00048

Measured yesterday against content hash 5120ac4d65a0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

436-code-generation-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

rules/400-patterns/436-code-generation-patterns.mdc · 92 lines

What it actually says

Code Generation Patterns

Purpose: Ensure professional-grade AI-generated code without common formatting errors.

Critical Patterns

Formatting Rules

# ✅ CORRECT Structure
def process():
    """Process data."""
    return data

# ❌ AVOID: Same-line docstrings
def bad(): """Wrong""" return None

Import Organization

# Standard → Third-party → Local
import os
import json

import numpy as np
import pandas as pd

from .utils import helper
from .models import DataModel

Error Handling

# Always include proper error handling
try:
    result = risky_operation()
except SpecificError as e:
    logger.error(f"Operation failed: {e}")
    raise ProcessingError(f"Cannot process: {e}") from e

Type Safety

from typing import List, Dict, Optional

def process_items(items: List[Dict[str, Any]]) -> Optional[pd.DataFrame]:
    """Process with full type hints."""
    if not items:
        return None
    return pd.DataFrame(items)

Common Pitfalls

  1. Missing newlines after docstrings/comments
  2. Incomplete imports - always specify full paths
  3. Bare exceptions - catch specific errors
  4. No type hints - add for public APIs
  5. Magic numbers - use named constants

Validation Checklist

  • Proper indentation (4 spaces)
  • Docstrings for public functions
  • Error handling for I/O operations
  • Type hints for parameters/returns
  • No trailing whitespace
  • Consistent quote style

Quick Fixes

# Auto-format Python
black --line-length 88 *.py

# Type checking
mypy --strict *.py

# Linting
ruff check --fix *.py
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 92 lines · 5 tokens per session scan A 5120ac4d65a0

Subscribe to this mod's changes

436-code-generation-patterns is a cursor rule published in the GitHub repository hamzaamjad/cursor-rules (2 stars, last pushed 1y ago), licensed MIT. It adds 5 tokens to every session and 477 once invoked, about $0.0000 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.