python-di 1.1.1

Description:

pythondi 1.1.1

python-di






Fully automatic dependency injection for python 3.7, 3.8, 3.9, pypy3 using (not only) argument annotations / type hints.
Corresponds to clean architecture patterns and ideal for business applications created in DDD / Hexagonal architecture flavour.
No external dependencies - uses only standard libraries.
Key features:

automatic type matching based on type hints / type annotations -
no manual configuration is needed, it just works out of the box
configurable object aggregation injection -
DI can join SomeClass objects and inject into argument annotated as Collection[SomeClass]
not harm existing codebase -
no decorators, no extra metadata are needed in existing codebase to make app construction possible
no singletons or global DI process state -
app or any app components can be instantiated independently as many times as needed
transparency of DI process -
static dependency graph and injection plan is built, informative exceptions on error cases
(like cyclic dependency or missing elements)

Help
Coming soon...
An Example
Application domain located in mod_simple.py:
from typing import List


class Repo:
def read(self) -> List[str]:
raise NotImplementedError


class DomainAction:
def __init__(self, repo: Repo):
self.repo = repo

def present(self) -> str:
joined = ", ".join(self.repo.read())
return f"Data found: {joined}"

Application concretes located in mod_simple_impl.py:
from typing import List

from mod_simple import Repo


class MockupRepo(Repo):
def read(self) -> List[str]:
return ["di", "test"]

Automatic application construction:
from di.declarative import DeclarativeApp, DeclarativeModule, scan_factories
import mod_simple, mod_simple_impl


def main():
# create app definition
app_def = DeclarativeApp(
DeclarativeModule(
# automatically add factories from `mod_simple` and `mod_simple_impl`
scan_factories(mod_simple, mod_simple_impl),
)
)

# build app
instance = app_def.build_instance()

# get initialized `DomainAction` object
action, = instance.values_by_type(mod_simple.DomainAction)

# check app works
assert action.present() == "Data found: di, test"

More examples
More working examples are available in tests/di/declarative/.
Please see tests/di/declarative/test_build.py for reference.