tools-only Add Type Hints
Use type annotations to make code self-documenting and catch errors early.
Why This Matters
Type hints provide:
- Static analysis - catch bugs before runtime
- Better IDE support - autocomplete, refactoring
- Documentation - types explain intent
- Confidence - easier refactoring
##❌ Incorrect
# ❌ No type hints
def get_user(id):
return users.get(id)
def process_order(order, discount):
if discount:
return order['total'] * (1 - discount)
return order['total']
✅ Correct
# ✅ Full type hints
from typing import Optional, Dict, Any
def get_user(id: int) -> Optional[Dict[str, Any]]:
"""Fetch user by ID.
Args:
id: User ID
Returns:
User dict or None if not found
"""
return users.get(id)
def process_order(order: Dict[str, Any], discount: Optional[float] = None) -> float:
"""Calculate order total with optional discount.
Args:
order: Order dictionary with 'total' key
discount: Discount rate (0.0-1.0), e.g. 0.1 for 10% off
Returns:
Final price after discount
"""
if discount:
return order['total'] * (1 - discount)
return order['total']
TypeScript
// ✅ Explicit types
interface User {
id: number;
name: string;
email: string;
}
function getUser(id: number): User | null {
return users.get(id) ?? null;
}
function processOrder(
order: { total: number },
discount?: number
): number {
if (discount) {
return order.total * (1 - discount);
}
return order.total;
}