Next, for the sake of the example, we’ll create a configuration type: > class Configuration. execute ( 'SELECT key, value FROM data ORDER by key' ). We’ll use an in-memory SQLite database for our example: > import sqlite3Īnd make up an imaginary RequestHandler class that uses the SQLiteĬonnection: > class RequestHandler. Here’s a full example to give you a taste of how Injector works: > from injector import Module, provider, Injector, inject, singleton Your code can run just fine without Injector orchestrating things. The client code only knows about dependency injection to the extentĪre simple markers that don’t really do anything on their own and To type-check correctly the code using it. Method is typed such that injector.get(SomeType) is staticallyĭeclared to return an instance of SomeType, therefore making it Provides as much static type safety as possible and only breaks it Or inject M圜lass into the place that needs it.Ĭooperation with static type checking infrastructure – the API This is simply because there’s no global Injector to use. Code like this won’t workįor this very reason: class M圜lass : def _init_ ( t : SomeType ): #. With different objects in different scopes. Instances as you like, each with a different configuration and each Injectable parameters, the class’ constructor remains a standardĬonstructor – you may instantiate the class just the same manually, Much “magic” (member injection, method injection).Ĭonnected to this, Injector tries to be as nonintrusive as possible.įor example while you may declare a class’ constructor to expect some Supporting them would be cumbersome and introduce a little bit too Additionally some features are omitted because
Providing a Pythonic API trumpsįaithfulness. Simplicity - while being inspired by Guice, Injector does not Inversion of Control Containers and the Dependency Injection pattern.The Clean Code Talks - Don’t Look For Things! (a talk by Miško.If you’re not sure what dependency injection is or you’d like to learn It automatically and transitively provides dependencies for you.Īs an added benefit, Injector encourages nicely compartmentalised code Lot of boiler-plate from larger applications. While dependency injection is easy to do in Python due to its supportįor keyword arguments, the ease with which objects can be mocked and itsĭynamic nature, a framework for assisting in this process can remove a
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