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

3 files changed, 6 insertions, 6 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):
diff --git a/lib/sqlalchemy/ext/declarative/base.py b/lib/sqlalchemy/ext/declarative/base.py
index 51ba35b4b..314e96cf1 100644
--- a/lib/sqlalchemy/ext/declarative/base.py
+++ b/lib/sqlalchemy/ext/declarative/base.py
@@ -22,9 +22,9 @@ from ...orm import synonym
 from ...orm.attributes import QueryableAttribute
 from ...orm.base import _is_mapped_class
 from ...orm.base import InspectionAttr
+from ...orm.descriptor_props import CompositeProperty
 from ...orm.interfaces import MapperProperty
 from ...orm.properties import ColumnProperty
-from ...orm.properties import CompositeProperty
 from ...schema import Column
 from ...schema import Table
 from ...sql import expression
diff --git a/lib/sqlalchemy/ext/declarative/clsregistry.py b/lib/sqlalchemy/ext/declarative/clsregistry.py
index 93e643cf5..71594aae7 100644
--- a/lib/sqlalchemy/ext/declarative/clsregistry.py
+++ b/lib/sqlalchemy/ext/declarative/clsregistry.py
@@ -16,10 +16,10 @@ from ... import exc
 from ... import inspection
 from ... import util
 from ...orm import class_mapper
+from ...orm import ColumnProperty
 from ...orm import interfaces
-from ...orm.properties import ColumnProperty
-from ...orm.properties import RelationshipProperty
-from ...orm.properties import SynonymProperty
+from ...orm import RelationshipProperty
+from ...orm import SynonymProperty
 from ...schema import _get_table_key