pynversify

Inversify for Python

A dependency injection container inspired by Inversify for Python.

This library supports hierarchical containers, various binding types (toSelf, to, constant, dynamic), and scopes (singleton and transient).

Examples

from inversify import Container, injectable, inject_params

class Token:
    def __init__(self, name):
        self.name = name
    def __hash__(self):
        return hash(self.name)
    def __eq__(self, other):
        return isinstance(other, Token) and self.name == other.name

# Tokens for bindings
LOGGER_TOKEN = Token("LOGGER")
USER_SERVICE_TOKEN = Token("USER_SERVICE")

@injectable
class Logger:
    def __init__(self):
        self.name = "Parent Logger"
    def log(self, message: str):
        print(f"[{self.name}]: {message}")

@injectable
class CustomLogger:
    def __init__(self):
        self.name = "Child Logger"
    def log(self, message: str):
        print(f"[{self.name}]: {message}")

@injectable
class UserService:
    @inject_params({'logger': LOGGER_TOKEN})
    def __init__(self, logger):
        self.logger = logger
    def process(self):
        self.logger.log("Processing in UserService")

# Create parent container and bind tokens
parent_container = Container()
parent_container.bind(LOGGER_TOKEN).to(Logger).inSingletonScope()
parent_container.bind(USER_SERVICE_TOKEN).to(UserService).inTransientScope()

# Create child container and override the LOGGER_TOKEN binding
child_container = parent_container.create_child()
child_container.bind(LOGGER_TOKEN).to(CustomLogger).inSingletonScope()

# Get services from parent and child containers
parent_service = parent_container.get(USER_SERVICE_TOKEN)
child_service = child_container.get(USER_SERVICE_TOKEN)

parent_service.process()  # Uses Parent Logger
child_service.process()   # Uses Child Logger