Clean up most py3k compat

Change-Id: I8172fdcc3103ff92aa049827728484c8779af6b7

17 files changed, 121 insertions, 177 deletions

diff --git a/lib/sqlalchemy/sql/base.py b/lib/sqlalchemy/sql/base.py
index b57da3289..2c74dd523 100644
--- a/lib/sqlalchemy/sql/base.py
+++ b/lib/sqlalchemy/sql/base.py
@@ -10,7 +10,10 @@
 """
 
 
+import collections.abc as collections_abc
+from functools import reduce
 import itertools
+from itertools import zip_longest
 import operator
 import re
 
@@ -27,7 +30,6 @@ from .. import util
 from ..util import HasMemoized
 from ..util import hybridmethod
 
-
 coercions = None
 elements = None
 type_api = None
@@ -176,7 +178,7 @@ def _cloned_difference(a, b):
     )
 
 
-class _DialectArgView(util.collections_abc.MutableMapping):
+class _DialectArgView(collections_abc.MutableMapping):
     """A dictionary view of dialect-level arguments in the form
     <dialectname>_<argument_name>.
 
@@ -236,7 +238,7 @@ class _DialectArgView(util.collections_abc.MutableMapping):
         )
 
 
-class _DialectArgDict(util.collections_abc.MutableMapping):
+class _DialectArgDict(collections_abc.MutableMapping):
     """A dictionary view of dialect-level arguments for a specific
     dialect.
 
@@ -615,7 +617,7 @@ class _MetaOptions(type):
         return o1
 
 
-class Options(util.with_metaclass(_MetaOptions)):
+class Options(metaclass=_MetaOptions):
     """A cacheable option dictionary with defaults."""
 
     def __init__(self, **kw):
@@ -638,7 +640,7 @@ class Options(util.with_metaclass(_MetaOptions)):
     def __eq__(self, other):
         # TODO: very inefficient.  This is used only in test suites
         # right now.
-        for a, b in util.zip_longest(self._cache_attrs, other._cache_attrs):
+        for a, b in zip_longest(self._cache_attrs, other._cache_attrs):
             if getattr(self, a) != getattr(other, b):
                 return False
         return True
@@ -1238,7 +1240,7 @@ class ColumnCollection:
         try:
             return self._index[key]
         except KeyError as err:
-            if isinstance(key, util.int_types):
+            if isinstance(key, int):
                 util.raise_(IndexError(key), replace_context=err)
             else:
                 raise
@@ -1251,7 +1253,7 @@ class ColumnCollection:
 
     def __contains__(self, key):
         if key not in self._index:
-            if not isinstance(key, util.string_types):
+            if not isinstance(key, str):
                 raise exc.ArgumentError(
                     "__contains__ requires a string argument"
                 )
@@ -1263,7 +1265,7 @@ class ColumnCollection:
         """Compare this :class:`_expression.ColumnCollection` to another
         based on the names of the keys"""
 
-        for l, r in util.zip_longest(self, other):
+        for l, r in zip_longest(self, other):
             if l is not r:
                 return False
         else:
@@ -1359,7 +1361,7 @@ class ColumnCollection:
     def contains_column(self, col):
         """Checks if a column object exists in this collection"""
         if col not in self._colset:
-            if isinstance(col, util.string_types):
+            if isinstance(col, str):
                 raise exc.ArgumentError(
                     "contains_column cannot be used with string arguments. "
                     "Use ``col_name in table.c`` instead."
@@ -1451,7 +1453,7 @@ class ColumnCollection:
                     # columns that have no reference to the target
                     # column (also occurs with CompoundSelect)
 
-                    col_distance = util.reduce(
+                    col_distance = reduce(
                         operator.add,
                         [
                             sc._annotations.get("weight", 1)
@@ -1459,7 +1461,7 @@ class ColumnCollection:
                             if sc.shares_lineage(column)
                         ],
                     )
-                    c_distance = util.reduce(
+                    c_distance = reduce(
                         operator.add,
                         [
                             sc._annotations.get("weight", 1)
diff --git a/lib/sqlalchemy/sql/coercions.py b/lib/sqlalchemy/sql/coercions.py
index f051ba12f..480d2c680 100644
--- a/lib/sqlalchemy/sql/coercions.py
+++ b/lib/sqlalchemy/sql/coercions.py
@@ -5,6 +5,7 @@
 # This module is part of SQLAlchemy and is released under
 # the MIT License: https://www.opensource.org/licenses/mit-license.php
 
+import collections.abc as collections_abc
 import numbers
 import re
 
@@ -17,7 +18,6 @@ from .visitors import Visitable
 from .. import exc
 from .. import inspection
 from .. import util
-from ..util import collections_abc
 
 
 elements = None
@@ -224,7 +224,7 @@ def expect_col_expression_collection(role, expressions):
         column = None
 
         resolved = expect(role, expr)
-        if isinstance(resolved, util.string_types):
+        if isinstance(resolved, str):
             strname = resolved = expr
         else:
             cols = []
@@ -303,7 +303,7 @@ class _ReturnsStringKey:
     def _implicit_coercions(
         self, original_element, resolved, argname=None, **kw
     ):
-        if isinstance(original_element, util.string_types):
+        if isinstance(original_element, str):
             return original_element
         else:
             self._raise_for_expected(original_element, argname, resolved)
@@ -362,7 +362,7 @@ class _NoTextCoercion:
     __slots__ = ()
 
     def _literal_coercion(self, element, argname=None, **kw):
-        if isinstance(element, util.string_types) and issubclass(
+        if isinstance(element, str) and issubclass(
             elements.TextClause, self._role_class
         ):
             _no_text_coercion(element, argname)
@@ -380,7 +380,7 @@ class _CoerceLiterals:
         return _no_text_coercion(element, argname)
 
     def _literal_coercion(self, element, argname=None, **kw):
-        if isinstance(element, util.string_types):
+        if isinstance(element, str):
             if self._coerce_star and element == "*":
                 return elements.ColumnClause("*", is_literal=True)
             else:
@@ -542,7 +542,7 @@ class InElementImpl(RoleImpl):
 
     def _literal_coercion(self, element, expr, operator, **kw):
         if isinstance(element, collections_abc.Iterable) and not isinstance(
-            element, util.string_types
+            element, str
         ):
             non_literal_expressions = {}
             element = list(element)
@@ -729,7 +729,7 @@ class TruncatedLabelImpl(_StringOnly, RoleImpl):
     def _implicit_coercions(
         self, original_element, resolved, argname=None, **kw
     ):
-        if isinstance(original_element, util.string_types):
+        if isinstance(original_element, str):
             return resolved
         else:
             self._raise_for_expected(original_element, argname, resolved)
@@ -844,7 +844,7 @@ class StatementImpl(_CoerceLiterals, RoleImpl):
 
     def _post_coercion(self, resolved, original_element, argname=None, **kw):
         if resolved is not original_element and not isinstance(
-            original_element, util.string_types
+            original_element, str
         ):
             # use same method as Connection uses; this will later raise
             # ObjectNotExecutableError
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 29aa57faa..0dd61d675 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -22,12 +22,13 @@ To generate user-defined SQL strings, see
 :doc:`/ext/compiler`.
 
 """
-
 import collections
+import collections.abc as collections_abc
 import contextlib
 import itertools
 import operator
 import re
+from time import perf_counter
 
 from . import base
 from . import coercions
@@ -453,7 +454,7 @@ class Compiled:
                 self.string = self.preparer._render_schema_translates(
                     self.string, schema_translate_map
                 )
-        self._gen_time = util.perf_counter()
+        self._gen_time = perf_counter()
 
     def _execute_on_connection(
         self, connection, distilled_params, execution_options
@@ -505,7 +506,7 @@ class Compiled:
         return self.construct_params()
 
 
-class TypeCompiler(util.with_metaclass(util.EnsureKWArgType, object)):
+class TypeCompiler(metaclass=util.EnsureKWArgType):
     """Produces DDL specification for TypeEngine objects."""
 
     ensure_kwarg = r"visit_\w+"
@@ -2026,10 +2027,8 @@ class SQLCompiler(Compiled):
 
         elif typ_dialect_impl._is_tuple_type or (
             typ_dialect_impl._isnull
-            and isinstance(values[0], util.collections_abc.Sequence)
-            and not isinstance(
-                values[0], util.string_types + util.binary_types
-            )
+            and isinstance(values[0], collections_abc.Sequence)
+            and not isinstance(values[0], (str, bytes))
         ):
 
             replacement_expression = (
@@ -2077,10 +2076,8 @@ class SQLCompiler(Compiled):
 
         elif typ_dialect_impl._is_tuple_type or (
             typ_dialect_impl._isnull
-            and isinstance(values[0], util.collections_abc.Sequence)
-            and not isinstance(
-                values[0], util.string_types + util.binary_types
-            )
+            and isinstance(values[0], collections_abc.Sequence)
+            and not isinstance(values[0], (str, bytes))
         ):
             assert not typ_dialect_impl._is_array
             to_update = [
@@ -4355,7 +4352,7 @@ class DDLCompiler(Compiled):
             except exc.CompileError as ce:
                 util.raise_(
                     exc.CompileError(
-                        util.u("(in table '%s', column '%s'): %s")
+                        "(in table '%s', column '%s'): %s"
                         % (table.description, column.name, ce.args[0])
                     ),
                     from_=ce,
@@ -4628,7 +4625,7 @@ class DDLCompiler(Compiled):
 
     def get_column_default_string(self, column):
         if isinstance(column.server_default, schema.DefaultClause):
-            if isinstance(column.server_default.arg, util.string_types):
+            if isinstance(column.server_default.arg, str):
                 return self.sql_compiler.render_literal_value(
                     column.server_default.arg, sqltypes.STRINGTYPE
                 )
@@ -5126,14 +5123,14 @@ class IdentifierPreparer:
         return (
             lc_value in self.reserved_words
             or value[0] in self.illegal_initial_characters
-            or not self.legal_characters.match(util.text_type(value))
+            or not self.legal_characters.match(str(value))
             or (lc_value != value)
         )
 
     def _requires_quotes_illegal_chars(self, value):
         """Return True if the given identifier requires quoting, but
         not taking case convention into account."""
-        return not self.legal_characters.match(util.text_type(value))
+        return not self.legal_characters.match(str(value))
 
     def quote_schema(self, schema, force=None):
         """Conditionally quote a schema name.
diff --git a/lib/sqlalchemy/sql/crud.py b/lib/sqlalchemy/sql/crud.py
index a9c9cb4c1..a313257ca 100644
--- a/lib/sqlalchemy/sql/crud.py
+++ b/lib/sqlalchemy/sql/crud.py
@@ -373,7 +373,7 @@ def _scan_cols(
         cols = [
             stmt.table.c[key]
             for key in parameter_ordering
-            if isinstance(key, util.string_types) and key in stmt.table.c
+            if isinstance(key, str) and key in stmt.table.c
         ] + [c for c in stmt.table.c if c.key not in ordered_keys]
 
     else:
diff --git a/lib/sqlalchemy/sql/ddl.py b/lib/sqlalchemy/sql/ddl.py
index f732ff2b0..74e7df821 100644
--- a/lib/sqlalchemy/sql/ddl.py
+++ b/lib/sqlalchemy/sql/ddl.py
@@ -180,7 +180,7 @@ class DDLElement(roles.DDLRole, Executable, _DDLCompiles):
         self.state = state
 
     def _should_execute(self, target, bind, **kw):
-        if isinstance(self.dialect, util.string_types):
+        if isinstance(self.dialect, str):
             if self.dialect != bind.engine.name:
                 return False
         elif isinstance(self.dialect, (tuple, list, set)):
@@ -288,7 +288,7 @@ class DDL(DDLElement):
 
         """
 
-        if not isinstance(statement, util.string_types):
+        if not isinstance(statement, str):
             raise exc.ArgumentError(
                 "Expected a string or unicode SQL statement, got '%r'"
                 % statement
diff --git a/lib/sqlalchemy/sql/dml.py b/lib/sqlalchemy/sql/dml.py
index e45c6b888..93cd912a7 100644
--- a/lib/sqlalchemy/sql/dml.py
+++ b/lib/sqlalchemy/sql/dml.py
@@ -9,6 +9,8 @@ Provide :class:`_expression.Insert`, :class:`_expression.Update` and
 :class:`_expression.Delete`.
 
 """
+import collections.abc as collections_abc
+
 from sqlalchemy.types import NullType
 from . import coercions
 from . import roles
@@ -31,7 +33,6 @@ from .selectable import ReturnsRows
 from .visitors import InternalTraversal
 from .. import exc
 from .. import util
-from ..util import collections_abc
 
 
 class DMLState(CompileState):
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py
index ca65f2112..76633cdd8 100644
--- a/lib/sqlalchemy/sql/elements.py
+++ b/lib/sqlalchemy/sql/elements.py
@@ -10,8 +10,6 @@
 
 """
 
-from __future__ import unicode_literals
-
 import itertools
 import operator
 import re
@@ -3869,7 +3867,7 @@ class BinaryExpression(ColumnElement):
     ):
         # allow compatibility with libraries that
         # refer to BinaryExpression directly and pass strings
-        if isinstance(operator, util.string_types):
+        if isinstance(operator, str):
             operator = operators.custom_op(operator)
         self._orig = (left.__hash__(), right.__hash__())
         self._propagate_attrs = left._propagate_attrs or right._propagate_attrs
@@ -4638,10 +4636,7 @@ class NamedColumn(ColumnElement):
 
     @util.memoized_property
     def description(self):
-        if util.py3k:
-            return self.name
-        else:
-            return self.name.encode("ascii", "backslashreplace")
+        return self.name
 
     @HasMemoized.memoized_attribute
     def _tq_key_label(self):
@@ -5068,7 +5063,7 @@ class ReleaseSavepointClause(_IdentifiedClause):
     __visit_name__ = "release_savepoint"
 
 
-class quoted_name(util.MemoizedSlots, util.text_type):
+class quoted_name(util.MemoizedSlots, str):
     """Represent a SQL identifier combined with quoting preferences.
 
     :class:`.quoted_name` is a Python unicode/str subclass which
@@ -5138,19 +5133,19 @@ class quoted_name(util.MemoizedSlots, util.text_type):
         return self
 
     def __reduce__(self):
-        return quoted_name, (util.text_type(self), self.quote)
+        return quoted_name, (str(self), self.quote)
 
     def _memoized_method_lower(self):
         if self.quote:
             return self
         else:
-            return util.text_type(self).lower()
+            return str(self).lower()
 
     def _memoized_method_upper(self):
         if self.quote:
             return self
         else:
-            return util.text_type(self).upper()
+            return str(self).upper()
 
 
 def _find_columns(clause):
@@ -5238,7 +5233,7 @@ class _truncated_label(quoted_name):
         return super(_truncated_label, cls).__new__(cls, value, quote)
 
     def __reduce__(self):
-        return self.__class__, (util.text_type(self), self.quote)
+        return self.__class__, (str(self), self.quote)
 
     def apply_map(self, map_):
         return self
@@ -5324,26 +5319,26 @@ class _anonymous_label(_truncated_label):
 
     def __add__(self, other):
         if "%" in other and not isinstance(other, _anonymous_label):
-            other = util.text_type(other).replace("%", "%%")
+            other = str(other).replace("%", "%%")
         else:
-            other = util.text_type(other)
+            other = str(other)
 
         return _anonymous_label(
             quoted_name(
-                util.text_type.__add__(self, other),
+                str.__add__(self, other),
                 self.quote,
             )
         )
 
     def __radd__(self, other):
         if "%" in other and not isinstance(other, _anonymous_label):
-            other = util.text_type(other).replace("%", "%%")
+            other = str(other).replace("%", "%%")
         else:
-            other = util.text_type(other)
+            other = str(other)
 
         return _anonymous_label(
             quoted_name(
-                util.text_type.__add__(other, self),
+                str.__add__(other, self),
                 self.quote,
             )
         )
diff --git a/lib/sqlalchemy/sql/functions.py b/lib/sqlalchemy/sql/functions.py
index 31f4fab0d..901a3a77c 100644
--- a/lib/sqlalchemy/sql/functions.py
+++ b/lib/sqlalchemy/sql/functions.py
@@ -55,7 +55,7 @@ def register_function(identifier, fn, package="_default"):
     """
     reg = _registry[package]
 
-    identifier = util.text_type(identifier).lower()
+    identifier = str(identifier).lower()
 
     # Check if a function with the same identifier is registered.
     if identifier in reg:
@@ -909,7 +909,7 @@ class _GenericMeta(TraversibleType):
         super(_GenericMeta, cls).__init__(clsname, bases, clsdict)
 
 
-class GenericFunction(util.with_metaclass(_GenericMeta, Function)):
+class GenericFunction(Function, metaclass=_GenericMeta):
     """Define a 'generic' function.
 
     A generic function is a pre-established :class:`.Function`
diff --git a/lib/sqlalchemy/sql/lambdas.py b/lib/sqlalchemy/sql/lambdas.py
index 110260799..2256fb5a9 100644
--- a/lib/sqlalchemy/sql/lambdas.py
+++ b/lib/sqlalchemy/sql/lambdas.py
@@ -5,6 +5,7 @@
 # This module is part of SQLAlchemy and is released under
 # the MIT License: https://www.opensource.org/licenses/mit-license.php
 
+import collections.abc as collections_abc
 import itertools
 import operator
 import sys
@@ -24,8 +25,6 @@ from .operators import ColumnOperators
 from .. import exc
 from .. import inspection
 from .. import util
-from ..util import collections_abc
-from ..util import compat
 
 _closure_per_cache_key = util.LRUCache(1000)
 
@@ -1111,7 +1110,7 @@ class AnalyzedFunction:
         code += "        return %s\n" % ", ".join("i%d" % i for i in argrange)
         code += "    return closure.__closure__"
         vars_ = {"o%d" % i: cell_values[i] for i in argrange}
-        compat.exec_(code, vars_, vars_)
+        exec(code, vars_, vars_)
         closure = vars_["make_cells"]()
 
         func = type(f)(
diff --git a/lib/sqlalchemy/sql/operators.py b/lib/sqlalchemy/sql/operators.py
index 675048cd0..6d45cd033 100644
--- a/lib/sqlalchemy/sql/operators.py
+++ b/lib/sqlalchemy/sql/operators.py
@@ -1394,7 +1394,7 @@ def _escaped_like_impl(fn, other, escape, autoescape):
         if escape is None:
             escape = "/"
 
-        if not isinstance(other, util.compat.string_types):
+        if not isinstance(other, str):
             raise TypeError("String value expected when autoescape=True")
 
         if escape not in ("%", "_"):
diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py
index 4bd49c468..eed2fbba1 100644
--- a/lib/sqlalchemy/sql/schema.py
+++ b/lib/sqlalchemy/sql/schema.py
@@ -28,8 +28,6 @@ Since these objects are part of the SQL expression language, they are usable
 as components in SQL expressions.
 
 """
-from __future__ import absolute_import
-
 import collections
 
 import sqlalchemy
@@ -1572,7 +1570,7 @@ class Column(DialectKWArgs, SchemaItem, ColumnClause):
         type_ = kwargs.pop("type_", None)
         args = list(args)
         if args:
-            if isinstance(args[0], util.string_types):
+            if isinstance(args[0], str):
                 if name is not None:
                     raise exc.ArgumentError(
                         "May not pass name positionally and as a keyword."
@@ -1819,7 +1817,7 @@ class Column(DialectKWArgs, SchemaItem, ColumnClause):
             )
 
         if self.index:
-            if isinstance(self.index, util.string_types):
+            if isinstance(self.index, str):
                 raise exc.ArgumentError(
                     "The 'index' keyword argument on Column is boolean only. "
                     "To create indexes with a specific name, create an "
@@ -1832,7 +1830,7 @@ class Column(DialectKWArgs, SchemaItem, ColumnClause):
             )
 
         elif self.unique:
-            if isinstance(self.unique, util.string_types):
+            if isinstance(self.unique, str):
                 raise exc.ArgumentError(
                     "The 'unique' keyword argument on Column is boolean "
                     "only. To create unique constraints or indexes with a "
@@ -2125,7 +2123,7 @@ class ForeignKey(DialectKWArgs, SchemaItem):
 
         self._colspec = coercions.expect(roles.DDLReferredColumnRole, column)
 
-        if isinstance(self._colspec, util.string_types):
+        if isinstance(self._colspec, str):
             self._table_column = None
         else:
             self._table_column = self._colspec
@@ -2395,7 +2393,7 @@ class ForeignKey(DialectKWArgs, SchemaItem):
 
         """
 
-        if isinstance(self._colspec, util.string_types):
+        if isinstance(self._colspec, str):
 
             parenttable, tablekey, colname = self._resolve_col_tokens()
 
@@ -2472,7 +2470,7 @@ class ForeignKey(DialectKWArgs, SchemaItem):
         table.foreign_keys.add(self)
         # set up remote ".column" attribute, or a note to pick it
         # up when the other Table/Column shows up
-        if isinstance(self._colspec, util.string_types):
+        if isinstance(self._colspec, str):
             parenttable, table_key, colname = self._resolve_col_tokens()
             fk_key = (table_key, colname)
             if table_key in parenttable.metadata.tables:
@@ -3068,9 +3066,7 @@ class DefaultClause(FetchedValue):
     has_argument = True
 
     def __init__(self, arg, for_update=False, _reflected=False):
-        util.assert_arg_type(
-            arg, (util.string_types[0], ClauseElement, TextClause), "arg"
-        )
+        util.assert_arg_type(arg, (str, ClauseElement, TextClause), "arg")
         super(DefaultClause, self).__init__(for_update)
         self.arg = arg
         self.reflected = _reflected
@@ -3264,7 +3260,7 @@ class ColumnCollectionMixin:
 
     def _col_expressions(self, table):
         return [
-            table.c[col] if isinstance(col, util.string_types) else col
+            table.c[col] if isinstance(col, str) else col
             for col in self._pending_colargs
         ]
 
@@ -4422,7 +4418,7 @@ class MetaData(SchemaItem):
             return "MetaData()"
 
     def __contains__(self, table_or_key):
-        if not isinstance(table_or_key, util.string_types):
+        if not isinstance(table_or_key, str):
             table_or_key = table_or_key.key
         return table_or_key in self.tables
 
@@ -4501,7 +4497,7 @@ class MetaData(SchemaItem):
     def _bind_to(self, bind):
         """Bind this MetaData to an Engine, Connection, string or URL."""
         url = util.preloaded.engine_url
-        if isinstance(bind, util.string_types + (url.URL,)):
+        if isinstance(bind, (str, url.URL)):
             self._bind = sqlalchemy.create_engine(bind)
         else:
             self._bind = bind
@@ -4838,7 +4834,7 @@ class ThreadLocalMetaData(MetaData):
     def _bind_to(self, bind):
         """Bind to a Connectable in the caller's thread."""
         url = util.preloaded.engine_url
-        if isinstance(bind, util.string_types + (url.URL,)):
+        if isinstance(bind, (str, url.URL)):
             try:
                 self.context._engine = self.__engines[bind]
             except KeyError:
diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index a04b205b5..a77cd173b 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -1624,10 +1624,7 @@ class AliasedReturnsRows(NoInit, FromClause):
         if isinstance(name, _anonymous_label):
             name = "anon_1"
 
-        if util.py3k:
-            return name
-        else:
-            return name.encode("ascii", "backslashreplace")
+        return name
 
     @property
     def original(self):
@@ -2728,10 +2725,7 @@ class TableClause(roles.DMLTableRole, Immutable, FromClause):
 
     @util.memoized_property
     def description(self):
-        if util.py3k:
-            return self.name
-        else:
-            return self.name.encode("ascii", "backslashreplace")
+        return self.name
 
     def append_column(self, c, **kw):
         existing = c.table
@@ -5267,9 +5261,7 @@ class Select(
                 isinstance(args[0], list)
                 or (
                     hasattr(args[0], "__iter__")
-                    and not isinstance(
-                        args[0], util.string_types + (ClauseElement,)
-                    )
+                    and not isinstance(args[0], (str, ClauseElement))
                     and inspect(args[0], raiseerr=False) is None
                     and not hasattr(args[0], "__clause_element__")
                 )
diff --git a/lib/sqlalchemy/sql/sqltypes.py b/lib/sqlalchemy/sql/sqltypes.py
index 1687c9f29..8874f0a83 100644
--- a/lib/sqlalchemy/sql/sqltypes.py
+++ b/lib/sqlalchemy/sql/sqltypes.py
@@ -9,9 +9,11 @@
 
 """
 
+import collections.abc as collections_abc
 import datetime as dt
 import decimal
 import json
+import pickle
 
 from . import coercions
 from . import elements
@@ -38,10 +40,8 @@ from .. import exc
 from .. import inspection
 from .. import processors
 from .. import util
-from ..util import compat
 from ..util import langhelpers
 from ..util import OrderedDict
-from ..util import pickle
 
 
 class _LookupExpressionAdapter:
@@ -192,7 +192,7 @@ class String(Concatenable, TypeEngine):
 
     @property
     def python_type(self):
-        return util.text_type
+        return str
 
     def get_dbapi_type(self, dbapi):
         return dbapi.STRING
@@ -721,7 +721,7 @@ class _Binary(TypeEngine):
 
     @property
     def python_type(self):
-        return util.binary_type
+        return bytes
 
     # Python 3 - sqlite3 doesn't need the `Binary` conversion
     # here, though pg8000 does to indicate "bytea"
@@ -753,7 +753,7 @@ class _Binary(TypeEngine):
     def coerce_compared_value(self, op, value):
         """See :meth:`.TypeEngine.coerce_compared_value` for a description."""
 
-        if isinstance(value, util.string_types):
+        if isinstance(value, str):
             return self
         else:
             return super(_Binary, self).coerce_compared_value(op, value)
@@ -1328,9 +1328,7 @@ class Enum(Emulated, String, SchemaType):
             # here between an INSERT statement and a criteria used in a SELECT,
             # for now we're staying conservative w/ behavioral changes (perhaps
             # someone has a trigger that handles strings on INSERT)
-            if not self.validate_strings and isinstance(
-                elem, compat.string_types
-            ):
+            if not self.validate_strings and isinstance(elem, str):
                 return elem
             else:
                 util.raise_(
@@ -1513,8 +1511,7 @@ class PickleType(TypeDecorator):
 
         :param protocol: defaults to ``pickle.HIGHEST_PROTOCOL``.
 
-        :param pickler: defaults to cPickle.pickle or pickle.pickle if
-          cPickle is not available.  May be any object with
+        :param pickler: defaults to pickle.  May be any object with
           pickle-compatible ``dumps`` and ``loads`` methods.
 
         :param comparator: a 2-arg callable predicate used
@@ -2123,7 +2120,7 @@ class JSON(Indexable, TypeEngine):
             def process(value):
                 if int_processor and isinstance(value, int):
                     value = int_processor(value)
-                elif string_processor and isinstance(value, util.string_types):
+                elif string_processor and isinstance(value, str):
                     value = string_processor(value)
                 return value
 
@@ -2136,7 +2133,7 @@ class JSON(Indexable, TypeEngine):
             def process(value):
                 if int_processor and isinstance(value, int):
                     value = int_processor(value)
-                elif string_processor and isinstance(value, util.string_types):
+                elif string_processor and isinstance(value, str):
                     value = string_processor(value)
                 return value
 
@@ -2178,8 +2175,8 @@ class JSON(Indexable, TypeEngine):
         """Define comparison operations for :class:`_types.JSON`."""
 
         def _setup_getitem(self, index):
-            if not isinstance(index, util.string_types) and isinstance(
-                index, compat.collections_abc.Sequence
+            if not isinstance(index, str) and isinstance(
+                index, collections_abc.Sequence
             ):
                 index = coercions.expect(
                     roles.BinaryElementRole,
@@ -2982,15 +2979,10 @@ _type_map = {
     dt.time: Time(),
     dt.timedelta: Interval(),
     util.NoneType: NULLTYPE,
+    bytes: LargeBinary(),
+    str: Unicode(),
 }
 
-if util.py3k:
-    _type_map[bytes] = LargeBinary()  # noqa
-    _type_map[str] = Unicode()
-else:
-    _type_map[unicode] = Unicode()  # noqa
-    _type_map[str] = String()
-
 
 _type_map_get = _type_map.get
 
diff --git a/lib/sqlalchemy/sql/traversals.py b/lib/sqlalchemy/sql/traversals.py
index 7973b535f..914a78dae 100644
--- a/lib/sqlalchemy/sql/traversals.py
+++ b/lib/sqlalchemy/sql/traversals.py
@@ -1,6 +1,8 @@
 from collections import deque
 from collections import namedtuple
+import collections.abc as collections_abc
 import itertools
+from itertools import zip_longest
 import operator
 
 from . import operators
@@ -8,9 +10,7 @@ from .visitors import ExtendedInternalTraversal
 from .visitors import InternalTraversal
 from .. import util
 from ..inspection import inspect
-from ..util import collections_abc
 from ..util import HasMemoized
-from ..util import py37
 
 SKIP_TRAVERSE = util.symbol("skip_traverse")
 COMPARE_FAILED = False
@@ -331,7 +331,7 @@ class CacheKey(namedtuple("CacheKey", ["key", "bindparams"])):
                 s1 = s1[idx]
                 s2 = s2[idx]
 
-            for idx, (e1, e2) in enumerate(util.zip_longest(s1, s2)):
+            for idx, (e1, e2) in enumerate(zip_longest(s1, s2)):
                 if idx < pickup_index:
                     continue
                 if e1 != e2:
@@ -669,38 +669,20 @@ class _CacheKey(ExtendedInternalTraversal):
         )
 
     def visit_dml_values(self, attrname, obj, parent, anon_map, bindparams):
-        if py37:
-            # in py37 we can assume two dictionaries created in the same
-            # insert ordering will retain that sorting
-            return (
-                attrname,
-                tuple(
-                    (
-                        k._gen_cache_key(anon_map, bindparams)
-                        if hasattr(k, "__clause_element__")
-                        else k,
-                        obj[k]._gen_cache_key(anon_map, bindparams),
-                    )
-                    for k in obj
-                ),
-            )
-        else:
-            expr_values = {k for k in obj if hasattr(k, "__clause_element__")}
-            if expr_values:
-                # expr values can't be sorted deterministically right now,
-                # so no cache
-                anon_map[NO_CACHE] = True
-                return ()
-
-            str_values = expr_values.symmetric_difference(obj)
-
-            return (
-                attrname,
-                tuple(
-                    (k, obj[k]._gen_cache_key(anon_map, bindparams))
-                    for k in sorted(str_values)
-                ),
-            )
+        # in py37 we can assume two dictionaries created in the same
+        # insert ordering will retain that sorting
+        return (
+            attrname,
+            tuple(
+                (
+                    k._gen_cache_key(anon_map, bindparams)
+                    if hasattr(k, "__clause_element__")
+                    else k,
+                    obj[k]._gen_cache_key(anon_map, bindparams),
+                )
+                for k in obj
+            ),
+        )
 
     def visit_dml_multi_values(
         self, attrname, obj, parent, anon_map, bindparams
@@ -1040,7 +1022,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
             for (
                 (left_attrname, left_visit_sym),
                 (right_attrname, right_visit_sym),
-            ) in util.zip_longest(
+            ) in zip_longest(
                 left._traverse_internals,
                 right._traverse_internals,
                 fillvalue=(None, None),
@@ -1098,7 +1080,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
     def visit_has_cache_key_list(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for l, r in util.zip_longest(left, right, fillvalue=None):
+        for l, r in zip_longest(left, right, fillvalue=None):
             if l._gen_cache_key(self.anon_map[0], []) != r._gen_cache_key(
                 self.anon_map[1], []
             ):
@@ -1114,7 +1096,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
     def visit_fromclause_canonical_column_collection(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for lcol, rcol in util.zip_longest(left, right, fillvalue=None):
+        for lcol, rcol in zip_longest(left, right, fillvalue=None):
             self.stack.append((lcol, rcol))
 
     def visit_fromclause_derived_column_collection(
@@ -1125,7 +1107,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
     def visit_string_clauseelement_dict(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for lstr, rstr in util.zip_longest(
+        for lstr, rstr in zip_longest(
             sorted(left), sorted(right), fillvalue=None
         ):
             if lstr != rstr:
@@ -1135,23 +1117,23 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
     def visit_clauseelement_tuples(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for ltup, rtup in util.zip_longest(left, right, fillvalue=None):
+        for ltup, rtup in zip_longest(left, right, fillvalue=None):
             if ltup is None or rtup is None:
                 return COMPARE_FAILED
 
-            for l, r in util.zip_longest(ltup, rtup, fillvalue=None):
+            for l, r in zip_longest(ltup, rtup, fillvalue=None):
                 self.stack.append((l, r))
 
     def visit_clauseelement_list(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for l, r in util.zip_longest(left, right, fillvalue=None):
+        for l, r in zip_longest(left, right, fillvalue=None):
             self.stack.append((l, r))
 
     def visit_clauseelement_tuple(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for l, r in util.zip_longest(left, right, fillvalue=None):
+        for l, r in zip_longest(left, right, fillvalue=None):
             self.stack.append((l, r))
 
     def _compare_unordered_sequences(self, seq1, seq2, **kw):
@@ -1174,7 +1156,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
     def visit_fromclause_ordered_set(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for l, r in util.zip_longest(left, right, fillvalue=None):
+        for l, r in zip_longest(left, right, fillvalue=None):
             self.stack.append((l, r))
 
     def visit_string(
@@ -1256,7 +1238,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
     def visit_prefix_sequence(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for (l_clause, l_str), (r_clause, r_str) in util.zip_longest(
+        for (l_clause, l_str), (r_clause, r_str) in zip_longest(
             left, right, fillvalue=(None, None)
         ):
             if l_str != r_str:
@@ -1271,7 +1253,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
         for (
             (l_target, l_onclause, l_from, l_flags),
             (r_target, r_onclause, r_from, r_flags),
-        ) in util.zip_longest(left, right, fillvalue=(None, None, None, None)):
+        ) in zip_longest(left, right, fillvalue=(None, None, None, None)):
             if l_flags != r_flags:
                 return COMPARE_FAILED
             self.stack.append((l_target, r_target))
@@ -1292,7 +1274,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
         right_keys = sorted(
             right, key=lambda elem: (elem[0].fullname, elem[1])
         )
-        for (ltable, ldialect), (rtable, rdialect) in util.zip_longest(
+        for (ltable, ldialect), (rtable, rdialect) in zip_longest(
             left_keys, right_keys, fillvalue=(None, None)
         ):
             if ldialect != rdialect:
@@ -1317,7 +1299,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
     ):
         # sequence of tuple pairs
 
-        for (lk, lv), (rk, rv) in util.zip_longest(
+        for (lk, lv), (rk, rv) in zip_longest(
             left, right, fillvalue=(None, None)
         ):
             if not self._compare_dml_values_or_ce(lk, rk, **kw):
@@ -1349,7 +1331,7 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
                     return COMPARE_FAILED
         elif isinstance(right, collections_abc.Sequence):
             return COMPARE_FAILED
-        elif py37:
+        else:
             # dictionaries guaranteed to support insert ordering in
             # py37 so that we can compare the keys in order.  without
             # this, we can't compare SQL expression keys because we don't
@@ -1359,25 +1341,15 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
                     return COMPARE_FAILED
                 if not self._compare_dml_values_or_ce(lv, rv, **kw):
                     return COMPARE_FAILED
-        else:
-            for lk in left:
-                lv = left[lk]
-
-                if lk not in right:
-                    return COMPARE_FAILED
-                rv = right[lk]
-
-                if not self._compare_dml_values_or_ce(lv, rv, **kw):
-                    return COMPARE_FAILED
 
     def visit_dml_multi_values(
         self, attrname, left_parent, left, right_parent, right, **kw
     ):
-        for lseq, rseq in util.zip_longest(left, right, fillvalue=None):
+        for lseq, rseq in zip_longest(left, right, fillvalue=None):
             if lseq is None or rseq is None:
                 return COMPARE_FAILED
 
-            for ld, rd in util.zip_longest(lseq, rseq, fillvalue=None):
+            for ld, rd in zip_longest(lseq, rseq, fillvalue=None):
                 if (
                     self.visit_dml_values(
                         attrname, left_parent, ld, right_parent, rd, **kw
diff --git a/lib/sqlalchemy/sql/type_api.py b/lib/sqlalchemy/sql/type_api.py
index 01763f266..82b8f538a 100644
--- a/lib/sqlalchemy/sql/type_api.py
+++ b/lib/sqlalchemy/sql/type_api.py
@@ -981,9 +981,7 @@ class ExternalType:
         return NO_CACHE
 
 
-class UserDefinedType(
-    util.with_metaclass(VisitableCheckKWArg, ExternalType, TypeEngine)
-):
+class UserDefinedType(ExternalType, TypeEngine, metaclass=VisitableCheckKWArg):
     """Base for user defined types.
 
     This should be the base of new types.  Note that
diff --git a/lib/sqlalchemy/sql/util.py b/lib/sqlalchemy/sql/util.py
index 6394c43a0..8aee6a97a 100644
--- a/lib/sqlalchemy/sql/util.py
+++ b/lib/sqlalchemy/sql/util.py
@@ -454,7 +454,7 @@ def bind_values(clause):
 
 
 def _quote_ddl_expr(element):
-    if isinstance(element, util.string_types):
+    if isinstance(element, str):
         element = element.replace("'", "''")
         return "'%s'" % element
     else:
diff --git a/lib/sqlalchemy/sql/visitors.py b/lib/sqlalchemy/sql/visitors.py
index deb92b081..b08080753 100644
--- a/lib/sqlalchemy/sql/visitors.py
+++ b/lib/sqlalchemy/sql/visitors.py
@@ -59,7 +59,7 @@ def _generate_compiler_dispatch(cls):
         cls._original_compiler_dispatch = cls._compiler_dispatch
         return
 
-    if not isinstance(visit_name, util.compat.string_types):
+    if not isinstance(visit_name, str):
         raise exc.InvalidRequestError(
             "__visit_name__ on class %s must be a string at the class level"
             % cls.__name__
@@ -114,7 +114,7 @@ class TraversibleType(type):
         super(TraversibleType, cls).__init__(clsname, bases, clsdict)
 
 
-class Traversible(util.with_metaclass(TraversibleType)):
+class Traversible(metaclass=TraversibleType):
     """Base class for visitable objects, applies the
     :class:`.visitors.TraversibleType` metaclass.
 
@@ -200,7 +200,7 @@ def _generate_dispatcher(visitor, internal_dispatch, method_name):
     return langhelpers._exec_code_in_env(meth_text, {}, method_name)
 
 
-class InternalTraversal(util.with_metaclass(_InternalTraversalType, object)):
+class InternalTraversal(metaclass=_InternalTraversalType):
     r"""Defines visitor symbols used for internal traversal.
 
     The :class:`.InternalTraversal` class is used in two ways.  One is that