issue_comments: 970624197

Here's the latest version of my weird dependency injection async class: ```python import inspect

class AsyncMeta(type): def new(cls, name, bases, attrs): # Decorate any items that are 'async def' methods _registry = {} new_attrs = {"_registry": _registry} for key, value in attrs.items(): if inspect.iscoroutinefunction(value) and not value.name == "resolve": new_attrs[key] = make_method(value) _registry[key] = new_attrs[key] else: new_attrs[key] = value

    # Topological sort of _registry by parameter dependencies
    graph = {
        key: {
            p for p in inspect.signature(method).parameters.keys()
            if p != "self" and not p.startswith("_")
        }
        for key, method in _registry.items()
    }
    new_attrs["_graph"] = graph
    return super().__new__(cls, name, bases, new_attrs)

def make_method(method): @wraps(method) async def inner(self, kwargs): parameters = inspect.signature(method).parameters.keys() # Any parameters not provided by kwargs are resolved from registry to_resolve = [p for p in parameters if p not in kwargs and p != "self"] missing = [p for p in to_resolve if p not in self._registry] assert ( not missing ), "The following DI parameters could not be found in the registry: {}".format( missing ) results = {} results.update(kwargs) results.update(await self.resolve(to_resolve)) return await method(self, results)

return inner

bad = [0]

class AsyncBase(metaclass=AsyncMeta): async def resolve(self, names): print(" resolve({})".format(names)) results = {} # Resolve them in the correct order ts = TopologicalSorter() ts2 = TopologicalSorter() print(" names = ", names) print(" self._graph = ", self._graph) for name in names: if self._graph[name]: ts.add(name, self._graph[name]) ts2.add(name, self._graph[name]) print(" static_order =", tuple(ts2.static_order())) ts.prepare() while ts.is_active(): print(" is_active, i = ", bad[0]) bad[0] += 1 if bad[0] > 20: print(" Infinite loop?") break nodes = ts.get_ready() print(" Do nodes:", nodes) awaitables = [self._registryname for name in nodes] print(" awaitables: ", awaitables) awaitable_results = await asyncio.gather(*awaitables) results.update({ p[0].name: p[1] for p in zip(awaitables, awaitable_results) }) print(results) for node in nodes: ts.done(node)

    return results

Example usage:python class Foo(AsyncBase): async def graa(self, boff): print("graa") return 5 async def boff(self): print("boff") return 8 async def other(self, boff, graa): print("other") return 5 + boff + graa

foo = Foo() await foo.other() Output: resolve(['boff', 'graa']) names = ['boff', 'graa'] self._graph = {'graa': {'boff'}, 'boff': set(), 'other': {'graa', 'boff'}} static_order = ('boff', 'graa') is_active, i = 0 Do nodes: ('boff',) awaitables: [<coroutine object Foo.boff at 0x10bd81a40>] resolve([]) names = [] self._graph = {'graa': {'boff'}, 'boff': set(), 'other': {'graa', 'boff'}} static_order = () boff {'boff': 8} is_active, i = 1 Do nodes: ('graa',) awaitables: [<coroutine object Foo.graa at 0x10d66b340>] resolve([]) names = [] self._graph = {'graa': {'boff'}, 'boff': set(), 'other': {'graa', 'boff'}} static_order = () graa {'boff': 8, 'graa': 5} other 18 ```