Provide special row proxies for count and index

The Python ``namedtuple()`` has the behavior such that the names ``count``
and ``index`` will be served as tuple values if the named tuple includes
those names; if they are absent, then their behavior as methods of
``collections.abc.Sequence`` is maintained. Therefore the
:class:`_result.Row` and :class:`_result.LegacyRow` classes have been fixed
so that they work in this same way, maintaining the expected behavior for
database rows that have columns named "index" or "count".

Fixes: #6074
Change-Id: I49a093da02f33f231d22ed5999c09fcaa3a68601

1 files changed, 21 insertions, 0 deletions

diff --git a/lib/sqlalchemy/engine/row.py b/lib/sqlalchemy/engine/row.py
index ac65d1b18..b870e6534 100644
--- a/lib/sqlalchemy/engine/row.py
+++ b/lib/sqlalchemy/engine/row.py
@@ -220,6 +220,27 @@ class Row(BaseRow, collections_abc.Sequence):
             self._data,
         )
 
+    def _special_name_accessor(name):
+        """Handle ambiguous names such as "count" and "index" """
+
+        @property
+        def go(self):
+            if self._parent._has_key(name):
+                return self.__getattr__(name)
+            else:
+
+                def meth(*arg, **kw):
+                    return getattr(collections_abc.Sequence, name)(
+                        self, *arg, **kw
+                    )
+
+                return meth
+
+        return go
+
+    count = _special_name_accessor("count")
+    index = _special_name_accessor("index")
+
     def __contains__(self, key):
         return key in self._data