HPI/my/core/source.py
Sean Breckenridge 8422c6e420
my.reddit: refactor into module that supports pushshift/gdpr (#179)
* initial pushshift/rexport merge implementation, using id for merging
* smarter module deprecation warning using regex
* add `RedditBase` from promnesia
* `import_source` helper for gracefully handing mixin data sources
2021-10-31 20:39:04 +00:00

63 lines
2.4 KiB
Python

"""
Decorator to gracefully handle importing a data source, or warning
and yielding nothing (or a default) when its not available
"""
from typing import Any, Iterator, TypeVar, Callable, Optional, Iterable, Any
from my.core.warnings import warn
from functools import wraps
# The factory function may produce something that has data
# similar to the shared model, but not exactly, so not
# making this a TypeVar, is just to make reading the
# type signature below a bit easier...
T = Any
# https://mypy.readthedocs.io/en/latest/generics.html?highlight=decorators#decorator-factories
FactoryF = TypeVar("FactoryF", bound=Callable[..., Iterator[T]])
_DEFUALT_ITR = ()
# tried to use decorator module but it really doesn't work well
# with types and kw-arguments... :/
def import_source(
default: Iterable[T] = _DEFUALT_ITR,
module_name: Optional[str] = None,
) -> Callable[..., Callable[..., Iterator[T]]]:
"""
doesn't really play well with types, but is used to catch
ModuleNotFoundError's for when modules aren't installed in
all.py files, so the types don't particularly matter
this is meant to be used to wrap some function which imports
and then yields an iterator of objects
If the user doesn't have that module installed, it returns
nothing and warns instead
"""
def decorator(factory_func: FactoryF) -> Callable[..., Iterator[T]]:
@wraps(factory_func)
def wrapper(*args, **kwargs) -> Iterator[T]:
try:
res = factory_func(**kwargs)
yield from res
except ModuleNotFoundError:
from . import core_config as CC
suppressed_in_conf = False
if module_name is not None and CC.config._is_module_active(module_name) is False:
suppressed_in_conf = True
if not suppressed_in_conf:
if module_name is None:
warn(f"Module {factory_func.__qualname__} could not be imported, or isn't configured propertly")
else:
warn(f"""Module {module_name} ({factory_func.__qualname__}) could not be imported, or isn't configured propertly\nTo hide this message, add {module_name} to your core config disabled_classes, like:
class core:
disabled_modules = [{repr(module_name)}]
""")
yield from default
return wrapper
return decorator