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, 1 insertions, 5 deletions

diff --git a/lib/sqlalchemy/exc.py b/lib/sqlalchemy/exc.py
index e51214fd9..77edf98a0 100644
--- a/lib/sqlalchemy/exc.py
+++ b/lib/sqlalchemy/exc.py
@@ -705,11 +705,7 @@ class LegacyAPIWarning(Base20DeprecationWarning):
     """indicates an API that is in 'legacy' status, a long term deprecation."""
 
 
-class RemovedIn20Warning(Base20DeprecationWarning):
-    """indicates an API that will be fully removed in SQLAlchemy 2.0."""
-
-
-class MovedIn20Warning(RemovedIn20Warning):
+class MovedIn20Warning(Base20DeprecationWarning):
     """Subtype of RemovedIn20Warning to indicate an API that moved only."""