Tips & Tricks

Reduce init boilerplate

Consider an order processing service that requires multiple dependencies. Here's how it looks with traditional initialization:

services/order_processor.py

@service
class OrderProcessor:
    def __init__(
        self,
        payment_gateway: PaymentGateway,
        inventory_service: InventoryService,
        order_repository: OrderRepository,
    ):
        self.payment_gateway = payment_gateway
        self.inventory_service = inventory_service
        self.order_repository = order_repository

Wireup lets you combine the @service decorator with dataclasses for a more concise syntax.

services/order_processor.py

from dataclasses import dataclass

@service
@dataclass
class OrderProcessor:
    payment_gateway: PaymentGateway
    inventory_service: InventoryService
    order_repository: OrderRepository

Using dataclasses eliminates the need to write the __init__ method and manually assign each dependency, while maintaining type hints and making the code more maintainable.

Aliased parameters

If you don't like having string parameters in your service objects you can alias them instead.

def awesome_function(env: Annotated[str, Inject(param="env")]) -> None: ...
def other_awesome_function(env: Annotated[str, Inject(param="env")]) -> None: ...

Using type aliases

EnvParameter = Annotated[str, Inject(param="env")]

def awesome_function(env: EnvParameter) -> None: ...
def other_awesome_function(env: EnvParameter) -> None: ...