Check that variables are used inside loops

Author: Cito

dbutils/simple_pooled_db.py

@@ -159,7 +159,7 @@ def __init__(self, dbapi, maxconnections, *args, **kwargs):
                 "Database module threading support cannot be determined.")
         # Establish all database connections (it would be better to
         # only establish a part of them now, and the rest on demand).
-        for i in range(maxconnections):
+        for _i in range(maxconnections):
             self.addConnection(dbapi.connect(*args, **kwargs))
 
     # The following functions are used with DB-API 2 modules

dbutils/simple_pooled_pg.py

@@ -122,7 +122,7 @@ def __init__(self, maxconnections, *args, **kwargs):
         self._queue = Queue(maxconnections)
         # Establish all database connections (it would be better to
         # only establish a part of them now, and the rest on demand).
-        for i in range(maxconnections):
+        for _i in range(maxconnections):
             self.cache(PgConnection(*args, **kwargs))
 
     def cache(self, con):

pyproject.toml

@@ -50,7 +50,6 @@ select = [
 ]
 # You can use `ruff rule ...` to see what these ignored rules check
 ignore = [
-  "B007",
   "B904",
   "E722",
   "N811",

tests/test_persistent_db.py

@@ -67,7 +67,7 @@ def test_threads(dbapi):  # noqa: F811
     num_threads = 3
     persist = PersistentDB(dbapi, closeable=True)
     query_queue, result_queue = [], []
-    for i in range(num_threads):
+    for _i in range(num_threads):
         query_queue.append(Queue(1))
         result_queue.append(Queue(1))
 
@@ -164,7 +164,7 @@ def test_setsession(dbapi):  # noqa: F811
     cursor.execute('set test')
     cursor.fetchone()
     cursor.close()
-    for i in range(3):
+    for _i in range(3):
         assert db._con.session == ['datestyle', 'test']
         cursor = db.cursor()
         cursor.execute('select test')

tests/test_persistent_pg.py

@@ -45,7 +45,7 @@ def test_threads():
     num_threads = 3
     persist = PersistentPg()
     query_queue, result_queue = [], []
-    for i in range(num_threads):
+    for _i in range(num_threads):
         query_queue.append(Queue(1))
         result_queue.append(Queue(1))
 
@@ -132,7 +132,7 @@ def test_setsession():
     assert db._setsession_sql == ('set datestyle',)
     assert db.db.session == ['datestyle']
     db.query('set test')
-    for i in range(3):
+    for _i in range(3):
         assert db.db.session == ['datestyle', 'test']
         db.query('select test')
     assert db.db.session == ['datestyle']

tests/test_pooled_db.py

@@ -275,7 +275,7 @@ def close(what=closed):
     if shareable:
         assert len(pool._shared_cache) == 0
     cache = []
-    for i in range(5):
+    for _i in range(5):
         cache.append(pool.connection())
     assert len(pool._idle_cache) == 5
     if shareable:
@@ -297,7 +297,7 @@ def close_shared(what=closed):
 
     if shareable:
         cache = []
-        for i in range(5):
+        for _i in range(5):
             cache.append(pool.connection())
         pool._shared_cache[3].con.close = close_shared
     else:
@@ -407,63 +407,64 @@ def test_min_max_cached(dbapi, threadsafety):  # noqa: F811
     shareable = threadsafety > 1
     pool = PooledDB(dbapi, 3)
     assert len(pool._idle_cache) == 3
-    cache = [pool.connection() for i in range(3)]
+    cache = [pool.connection() for _i in range(3)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 3
-    cache = [pool.connection() for i in range(6)]
+    cache = [pool.connection() for _i in range(6)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 6
     pool = PooledDB(dbapi, 0, 3)
     assert len(pool._idle_cache) == 0
-    cache = [pool.connection() for i in range(3)]
+    cache = [pool.connection() for _i in range(3)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 3
-    cache = [pool.connection() for i in range(6)]
+    cache = [pool.connection() for _i in range(6)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 3
     pool = PooledDB(dbapi, 3, 3)
     assert len(pool._idle_cache) == 3
-    cache = [pool.connection() for i in range(3)]
+    cache = [pool.connection() for _i in range(3)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 3
-    cache = [pool.connection() for i in range(6)]
+    cache = [pool.connection() for _i in range(6)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 3
     pool = PooledDB(dbapi, 3, 2)
     assert len(pool._idle_cache) == 3
-    cache = [pool.connection() for i in range(4)]
+    cache = [pool.connection() for _i in range(4)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 3
     pool = PooledDB(dbapi, 2, 5)
     assert len(pool._idle_cache) == 2
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     assert len(pool._idle_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 5
     pool = PooledDB(dbapi, 1, 2, 3)
     assert len(pool._idle_cache) == 1
-    cache = [pool.connection(False) for i in range(4)]
+    cache = [pool.connection(False) for _i in range(4)]
     assert len(pool._idle_cache) == 0
     if shareable:
         assert len(pool._shared_cache) == 0
+    assert cache
     del cache
     assert len(pool._idle_cache) == 2
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     assert len(pool._idle_cache) == 0
     if shareable:
         assert len(pool._shared_cache) == 3
@@ -474,14 +475,14 @@ def test_min_max_cached(dbapi, threadsafety):  # noqa: F811
         assert len(pool._shared_cache) == 0
     pool = PooledDB(dbapi, 1, 3, 2)
     assert len(pool._idle_cache) == 1
-    cache = [pool.connection(False) for i in range(4)]
+    cache = [pool.connection(False) for _i in range(4)]
     assert len(pool._idle_cache) == 0
     if shareable:
         assert len(pool._shared_cache) == 0
     assert cache
     del cache
     assert len(pool._idle_cache) == 3
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     if shareable:
         assert len(pool._idle_cache) == 1
         assert len(pool._shared_cache) == 2
@@ -500,34 +501,34 @@ def test_max_shared(dbapi, threadsafety):  # noqa: F811
     shareable = threadsafety > 1
     pool = PooledDB(dbapi)
     assert len(pool._idle_cache) == 0
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     assert len(cache) == 10
     assert len(pool._idle_cache) == 0
     pool = PooledDB(dbapi, 1, 1, 0)
     assert len(pool._idle_cache) == 1
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     assert len(cache) == 10
     assert len(pool._idle_cache) == 0
     pool = PooledDB(dbapi, 0, 0, 1)
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     assert len(cache) == 10
     assert len(pool._idle_cache) == 0
     if shareable:
         assert len(pool._shared_cache) == 1
     pool = PooledDB(dbapi, 1, 1, 1)
     assert len(pool._idle_cache) == 1
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     assert len(cache) == 10
     assert len(pool._idle_cache) == 0
     if shareable:
         assert len(pool._shared_cache) == 1
     pool = PooledDB(dbapi, 0, 0, 7)
-    cache = [pool.connection(False) for i in range(3)]
+    cache = [pool.connection(False) for _i in range(3)]
     assert len(cache) == 3
     assert len(pool._idle_cache) == 0
     if shareable:
         assert len(pool._shared_cache) == 0
-    cache = [pool.connection() for i in range(10)]
+    cache = [pool.connection() for _i in range(10)]
     assert len(cache) == 10
     assert len(pool._idle_cache) == 3
     if shareable:
@@ -537,7 +538,7 @@ def test_max_shared(dbapi, threadsafety):  # noqa: F811
 def test_sort_shared(dbapi):  # noqa: F811
     pool = PooledDB(dbapi, 0, 4, 4)
     cache = []
-    for i in range(6):
+    for _i in range(6):
         db = pool.connection()
         db.cursor().execute('select test')
         cache.append(db)
@@ -559,7 +560,7 @@ def test_equally_shared(dbapi, threadsafety):  # noqa: F811
     shareable = threadsafety > 1
     pool = PooledDB(dbapi, 5, 5, 5)
     assert len(pool._idle_cache) == 5
-    for i in range(15):
+    for _i in range(15):
         db = pool.connection(False)
         db.cursor().execute('select test')
         db.close()
@@ -569,7 +570,7 @@ def test_equally_shared(dbapi, threadsafety):  # noqa: F811
         assert con._usage == 3
         assert con._con.num_queries == 3
     cache = []
-    for i in range(35):
+    for _i in range(35):
         db = pool.connection()
         db.cursor().execute('select test')
         cache.append(db)
@@ -595,7 +596,7 @@ def test_many_shared(dbapi, threadsafety):  # noqa: F811
     shareable = threadsafety > 1
     pool = PooledDB(dbapi, 0, 0, 5)
     cache = []
-    for i in range(35):
+    for _i in range(35):
         db = pool.connection()
         db.cursor().execute('select test1')
         db.cursor().execute('select test2')
@@ -622,7 +623,7 @@ def test_many_shared(dbapi, threadsafety):  # noqa: F811
         for db in cache:
             if db:
                 db.cursor().callproc('test4')
-        for i in range(6):
+        for _i in range(6):
             db = pool.connection()
             db.cursor().callproc('test4')
             cache.append(db)
@@ -685,7 +686,7 @@ def test_maxconnections(dbapi, threadsafety):  # noqa: F811, PLR0915
     assert pool._connections == 0
     assert len(pool._idle_cache) == 1
     cache = []
-    for i in range(3):
+    for _i in range(3):
         cache.append(pool.connection(False))
     assert pool._connections == 3
     assert len(pool._idle_cache) == 0
@@ -700,7 +701,7 @@ def test_maxconnections(dbapi, threadsafety):  # noqa: F811, PLR0915
     assert len(pool._idle_cache) == 2
     if shareable:
         assert len(pool._shared_cache) == 0
-    for i in range(3):
+    for _i in range(3):
         cache.append(pool.connection())
     assert len(pool._idle_cache) == 0
     if shareable:
@@ -794,7 +795,7 @@ def test_maxconnections(dbapi, threadsafety):  # noqa: F811, PLR0915
     assert pool._connections == 0
     assert len(pool._idle_cache) == 4
     cache = []
-    for i in range(4):
+    for _i in range(4):
         cache.append(pool.connection(False))
     assert pool._connections == 4
     assert len(pool._idle_cache) == 0
@@ -806,7 +807,7 @@ def test_maxconnections(dbapi, threadsafety):  # noqa: F811, PLR0915
     assert pool._maxconnections == 4
     assert pool._connections == 0
     assert len(pool._idle_cache) == 1
-    for i in range(4):
+    for _i in range(4):
         cache.append(pool.connection())
     assert len(pool._idle_cache) == 0
     if shareable:
@@ -826,7 +827,7 @@ def test_maxconnections(dbapi, threadsafety):  # noqa: F811, PLR0915
     assert pool._maxconnections == 3
     assert pool._connections == 0
     cache = []
-    for i in range(3):
+    for _i in range(3):
         cache.append(pool.connection(False))
     assert pool._connections == 3
     with pytest.raises(TooManyConnections):
@@ -835,11 +836,11 @@ def test_maxconnections(dbapi, threadsafety):  # noqa: F811, PLR0915
         pool.connection(True)
     cache = []
     assert pool._connections == 0
-    for i in range(3):
+    for _i in range(3):
         cache.append(pool.connection())
     assert pool._connections == 3
     if shareable:
-        for i in range(3):
+        for _i in range(3):
             cache.append(pool.connection())
         assert pool._connections == 3
     else:
@@ -851,7 +852,7 @@ def test_maxconnections(dbapi, threadsafety):  # noqa: F811, PLR0915
     assert pool._maxconnections == 0
     assert pool._connections == 0
     cache = []
-    for i in range(10):
+    for _i in range(10):
         cache.append(pool.connection(False))
         cache.append(pool.connection())
     if shareable:
@@ -967,40 +968,40 @@ def test_one_thread_two_connections(dbapi, threadsafety):  # noqa: F811
     shareable = threadsafety > 1
     pool = PooledDB(dbapi, 2)
     db1 = pool.connection()
-    for i in range(5):
+    for _i in range(5):
         db1.cursor().execute('select test')
     db2 = pool.connection()
     assert db1 != db2
     assert db1._con != db2._con
-    for i in range(7):
+    for _i in range(7):
         db2.cursor().execute('select test')
     assert db1._con._con.num_queries == 5
     assert db2._con._con.num_queries == 7
     del db1
     db1 = pool.connection()
     assert db1 != db2
     assert db1._con != db2._con
-    for i in range(3):
+    for _i in range(3):
         db1.cursor().execute('select test')
     assert db1._con._con.num_queries == 8
     db2.cursor().execute('select test')
     assert db2._con._con.num_queries == 8
     pool = PooledDB(dbapi, 0, 0, 2)
     db1 = pool.connection()
-    for i in range(5):
+    for _i in range(5):
         db1.cursor().execute('select test')
     db2 = pool.connection()
     assert db1 != db2
     assert db1._con != db2._con
-    for i in range(7):
+    for _i in range(7):
         db2.cursor().execute('select test')
     assert db1._con._con.num_queries == 5
     assert db2._con._con.num_queries == 7
     del db1
     db1 = pool.connection()
     assert db1 != db2
     assert db1._con != db2._con
-    for i in range(3):
+    for _i in range(3):
         db1.cursor().execute('select test')
     assert db1._con._con.num_queries == 8
     db2.cursor().execute('select test')
@@ -1028,7 +1029,7 @@ def test_three_threads_two_connections(dbapi, threadsafety):  # noqa: F811
     def connection():
         queue.put(pool.connection(), timeout=1)
 
-    for i in range(3):
+    for _i in range(3):
         Thread(target=connection).start()
     db1 = queue.get(timeout=1)
     db2 = queue.get(timeout=1)