Issue #10203: sqlite3.Row now truly supports sequence protocol. In particulr

it supports reverse() and negative indices.  Original patch by Claudiu Popa.

2 files changed, 25 insertions, 3 deletions

diff --git a/Lib/sqlite3/dbapi2.py b/Lib/sqlite3/dbapi2.py
index 9a0b76645e..991682ce9e 100644
--- a/Lib/sqlite3/dbapi2.py
+++ b/Lib/sqlite3/dbapi2.py
@@ -22,6 +22,7 @@
 
 import datetime
 import time
+import collections.abc
 
 from _sqlite3 import *
 
@@ -50,6 +51,7 @@ version_info = tuple([int(x) for x in version.split(".")])
 sqlite_version_info = tuple([int(x) for x in sqlite_version.split(".")])
 
 Binary = memoryview
+collections.abc.Sequence.register(Row)
 
 def register_adapters_and_converters():
     def adapt_date(val):
diff --git a/Lib/sqlite3/test/factory.py b/Lib/sqlite3/test/factory.py
index 1013755b9c..98dcae5d6c 100644
--- a/Lib/sqlite3/test/factory.py
+++ b/Lib/sqlite3/test/factory.py
@@ -23,6 +23,7 @@
 
 import unittest
 import sqlite3 as sqlite
+from collections.abc import Sequence
 
 class MyConnection(sqlite.Connection):
     def __init__(self, *args, **kwargs):
@@ -96,9 +97,19 @@ class RowFactoryTests(unittest.TestCase):
         self.assertEqual(col1, 1, "by name: wrong result for column 'A'")
         self.assertEqual(col2, 2, "by name: wrong result for column 'B'")
 
-        col1, col2 = row[0], row[1]
-        self.assertEqual(col1, 1, "by index: wrong result for column 0")
-        self.assertEqual(col2, 2, "by index: wrong result for column 1")
+        self.assertEqual(row[0], 1, "by index: wrong result for column 0")
+        self.assertEqual(row[1], 2, "by index: wrong result for column 1")
+        self.assertEqual(row[-1], 2, "by index: wrong result for column -1")
+        self.assertEqual(row[-2], 1, "by index: wrong result for column -2")
+
+        with self.assertRaises(IndexError):
+            row['c']
+        with self.assertRaises(IndexError):
+            row[2]
+        with self.assertRaises(IndexError):
+            row[-3]
+        with self.assertRaises(IndexError):
+            row[2**1000]
 
     def CheckSqliteRowIter(self):
         """Checks if the row object is iterable"""
@@ -142,6 +153,15 @@ class RowFactoryTests(unittest.TestCase):
         self.assertNotEqual(row_1, row_3)
         self.assertNotEqual(hash(row_1), hash(row_3))
 
+    def CheckSqliteRowAsSequence(self):
+        """ Checks if the row object can act like a sequence """
+        self.con.row_factory = sqlite.Row
+        row = self.con.execute("select 1 as a, 2 as b").fetchone()
+
+        as_tuple = tuple(row)
+        self.assertEqual(list(reversed(row)), list(reversed(as_tuple)))
+        self.assertIsInstance(row, Sequence)
+
     def tearDown(self):
         self.con.close()