18、Python 中的依赖注入与引导脚本实践

Python 中的依赖注入与引导脚本实践

1. 依赖注入的实现方式

1.1 闭包和偏函数实现依赖注入

在 Python 中，可以使用闭包和偏函数来实现依赖注入。以下是一个示例代码：

def bootstrap(..):
    uow = unit_of_work.SqlAlchemyUnitOfWork()
    # prepare a version of the allocate fn with UoW dependency captured in a closure
    allocate_composed = lambda cmd: allocate(cmd, uow)
    # or, equivalently (this gets you a nicer stack trace)
    def allocate_composed(cmd):
        return allocate(cmd, uow)
    # alternatively with a partial
    import functools
    allocate_composed = functools.partial(allocate, uow=uow)  

# later at runtime, we can call the partial function, and it will have
# the UoW already bound
allocate_composed(cmd)

闭包（如 lambda 表达式或命名函数）和 functools.p