Import from collections.abc

Fixed additional warnings generated by Python 3.7 due to changes in the
organization of the Python ``collections`` and ``collections.abc`` packages.
Previous ``collections`` warnings were fixed in version 1.2.11. Pull request
courtesy xtreak.

See I2d1c0ef97c8ecac7af152cc56263422a40faa6bb for the original collections.abc
fixes.

Fixes: #4339
Change-Id: Ia92d2461f20309fb33ea6c6f592f7d4e7e32ae7a
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/475

4 files changed, 6 insertions, 9 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/json.py b/lib/sqlalchemy/dialects/postgresql/json.py
index 740118030..1a1367f1b 100644
--- a/lib/sqlalchemy/dialects/postgresql/json.py
+++ b/lib/sqlalchemy/dialects/postgresql/json.py
@@ -7,7 +7,6 @@
 from __future__ import absolute_import
 
 import json
-import collections
 
 from .base import ischema_names, colspecs
 from ... import types as sqltypes
@@ -61,7 +60,7 @@ class JSONPathType(sqltypes.JSON.JSONPathType):
         super_proc = self.string_bind_processor(dialect)
 
         def process(value):
-            assert isinstance(value, collections.Sequence)
+            assert isinstance(value, util.collections_abc.Sequence)
             tokens = [util.text_type(elem)for elem in value]
             value = "{%s}" % (", ".join(tokens))
             if super_proc:
@@ -74,7 +73,7 @@ class JSONPathType(sqltypes.JSON.JSONPathType):
         super_proc = self.string_literal_processor(dialect)
 
         def process(value):
-            assert isinstance(value, collections.Sequence)
+            assert isinstance(value, util.collections_abc.Sequence)
             tokens = [util.text_type(elem)for elem in value]
             value = "{%s}" % (", ".join(tokens))
             if super_proc:
diff --git a/lib/sqlalchemy/engine/result.py b/lib/sqlalchemy/engine/result.py
index ed6c0251d..d4c862375 100644
--- a/lib/sqlalchemy/engine/result.py
+++ b/lib/sqlalchemy/engine/result.py
@@ -179,8 +179,7 @@ class RowProxy(BaseRowProxy):
 try:
     # Register RowProxy with Sequence,
     # so sequence protocol is implemented
-    from collections import Sequence
-    Sequence.register(RowProxy)
+    util.collections_abc.Sequence.register(RowProxy)
 except ImportError:
     pass
 
diff --git a/lib/sqlalchemy/sql/base.py b/lib/sqlalchemy/sql/base.py
index 9c79ccf7a..5c884e1a0 100644
--- a/lib/sqlalchemy/sql/base.py
+++ b/lib/sqlalchemy/sql/base.py
@@ -14,7 +14,6 @@ from .. import util, exc
 import itertools
 from .visitors import ClauseVisitor
 import re
-import collections
 
 PARSE_AUTOCOMMIT = util.symbol('PARSE_AUTOCOMMIT')
 NO_ARG = util.symbol('NO_ARG')
@@ -46,7 +45,7 @@ def _generative(fn, *args, **kw):
     return self
 
 
-class _DialectArgView(collections.MutableMapping):
+class _DialectArgView(util.collections_abc.MutableMapping):
     """A dictionary view of dialect-level arguments in the form
     <dialectname>_<argument_name>.
 
@@ -99,7 +98,7 @@ class _DialectArgView(collections.MutableMapping):
         )
 
 
-class _DialectArgDict(collections.MutableMapping):
+class _DialectArgDict(util.collections_abc.MutableMapping):
     """A dictionary view of dialect-level arguments for a specific
     dialect.
 
diff --git a/lib/sqlalchemy/sql/sqltypes.py b/lib/sqlalchemy/sql/sqltypes.py
index 08af78606..ef0de2a92 100644
--- a/lib/sqlalchemy/sql/sqltypes.py
+++ b/lib/sqlalchemy/sql/sqltypes.py
@@ -2098,7 +2098,7 @@ class JSON(Indexable, TypeEngine):
         @util.dependencies('sqlalchemy.sql.default_comparator')
         def _setup_getitem(self, default_comparator, index):
             if not isinstance(index, util.string_types) and \
-                    isinstance(index, collections.Sequence):
+                    isinstance(index, compat.collections_abc.Sequence):
                 index = default_comparator._check_literal(
                     self.expr, operators.json_path_getitem_op,
                     index, bindparam_type=JSON.JSONPathType