from collections import defaultdict

# Example: Grouping orders by customer ID
orders = [
    {"order_id": 101, "customer_id": "cust_A", "amount": 150.0},
    {"order_id": 102, "customer_id": "cust_B", "amount": 200.0},
    {"order_id": 103, "customer_id": "cust_A", "amount": 50.0},
    {"order_id": 104, "customer_id": "cust_C", "amount": 300.0},
    {"order_id": 105, "customer_id": "cust_B", "amount": 75.0},
]

orders_by_customer = defaultdict(list)
for order in orders:
    orders_by_customer[order["customer_id"]].append(order)

print(f"Orders grouped by customer: {dict(orders_by_customer)}")

# Example 2: Grouping API endpoints by method
endpoints = [
    {"path": "/users", "method": "GET", "handler": "get_users"},
    {"path": "/users", "method": "POST", "handler": "create_user"},
    {"path": "/products/{id}", "method": "GET", "handler": "get_product"},
    {"path": "/users/{id}", "method": "DELETE", "handler": "delete_user"},
]

endpoints_by_method = defaultdict(list)
for ep in endpoints:
    endpoints_by_method[ep["method"]].append(ep["path"])

print(f"Endpoints grouped by method: {dict(endpoints_by_method)}")