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

my/core/cfg.py

@@ -10,7 +10,7 @@ C = TypeVar('C')
 def make_config(cls: Type[C], migration: Callable[[Attrs], Attrs]=lambda x: x) -> C:
     user_config = cls.__base__
     old_props = {
-        # NOTE: deliberately use gettatr to 'force' lcass properties here
+        # NOTE: deliberately use gettatr to 'force' class properties here
         k: getattr(user_config, k) for k in vars(user_config)
     }
     new_props = migration(old_props)

my/core/source.py

@@ -0,0 +1,63 @@
+"""
+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
+