Simplified module pre-loading strategy and made it linter friendly

Introduced a modules registry to register modules that should be lazily loaded
in the package init. This ensures that they are in the system module cache,
avoiding potential thread safety issues as when importing them directly
in the function that uses them. The module registry is used to obtain
these modules directly, ensuring that the all the lazily loaded modules
are resolved at the proper time

This replaces dependency_for decorator and the dependencies decorator logic,
removing the need to pass the resolved modules as arguments of the
decodated functions and removes possible errors caused by linters.

Fixes: #4689
Fixes: #4656
Change-Id: I2e291eba4297867fc0ddb5d875b9f7af34751d01

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/sqlalchemy/ext/declarative/api.py b/lib/sqlalchemy/ext/declarative/api.py
index c8695b7bf..ca7d3a022 100644
--- a/lib/sqlalchemy/ext/declarative/api.py
+++ b/lib/sqlalchemy/ext/declarative/api.py
@@ -23,7 +23,7 @@ from ...orm import attributes
 from ...orm import comparable_property
 from ...orm import exc as orm_exc
 from ...orm import interfaces
-from ...orm import properties
+from ...orm import relationships
 from ...orm import synonym as _orm_synonym
 from ...orm.base import _inspect_mapped_class
 from ...orm.base import _mapper_or_none
@@ -761,7 +761,7 @@ class DeferredReflection(object):
             metadata = mapper.class_.metadata
             for rel in mapper._props.values():
                 if (
-                    isinstance(rel, properties.RelationshipProperty)
+                    isinstance(rel, relationships.RelationshipProperty)
                     and rel.secondary is not None
                 ):
                     if isinstance(rel.secondary, Table):