Remove all remaining removed_in_20 warnings slated for removal

Finalize all remaining removed-in-2.0 changes so that we
can begin doing pep-484 typing without old things
getting in the way (we will also have to do public_factory).

note there are a few "moved_in_20()" and "became_legacy_in_20()"
warnings still in place.  The SQLALCHEMY_WARN_20 variable
is now removed.

Also removed here are the legacy "in place mutators" for Select
statements, and some keyword-only argument signatures in Core
have been added.

Also in the big change department, the ORM mapper() function
is removed entirely; the Mapper class is otherwise unchanged,
just the public-facing API function.  Mappers are now always
given a registry in which to participate, however the
argument signature of Mapper is not changed. ideally "registry"
would be the first positional argument.

Fixes: #7257

Change-Id: Ic70c57b9f1cf7eb996338af5183b11bdeb3e1623

1 files changed, 2 insertions, 3 deletions

diff --git a/lib/sqlalchemy/ext/mutable.py b/lib/sqlalchemy/ext/mutable.py
index 7e277d379..7a497abfc 100644
--- a/lib/sqlalchemy/ext/mutable.py
+++ b/lib/sqlalchemy/ext/mutable.py
@@ -360,7 +360,6 @@ from .. import event
 from .. import inspect
 from .. import types
 from ..orm import Mapper
-from ..orm import mapper
 from ..orm.attributes import flag_modified
 from ..sql.base import SchemaEventTarget
 from ..util import memoized_property
@@ -567,7 +566,7 @@ class Mutable(MutableBase):
                 if isinstance(prop.columns[0].type, sqltype):
                     cls.associate_with_attribute(getattr(class_, prop.key))
 
-        event.listen(mapper, "mapper_configured", listen_for_type)
+        event.listen(Mapper, "mapper_configured", listen_for_type)
 
     @classmethod
     def as_mutable(cls, sqltype):
@@ -629,7 +628,7 @@ class Mutable(MutableBase):
                 ) or (prop.columns[0].type is sqltype):
                     cls.associate_with_attribute(getattr(class_, prop.key))
 
-        event.listen(mapper, "mapper_configured", listen_for_type)
+        event.listen(Mapper, "mapper_configured", listen_for_type)
 
         return sqltype