linting.

.github/workflows/tests.yml

@@ -165,13 +165,12 @@ jobs:
         with:
           name: RelStorage-${{ runner.os }}-${{ matrix.python-version }}.whl
           path: dist/*whl
-      # XXX: Temp comment out linting until tests run again.
-      # - name: lint
-      #   if: matrix.python-version == '3.11' && startsWith(runner.os, 'Linux')
-      #   # At this writing, PyLint 2.17/astroid 2.15 won't work on 3.12
-      #   run: |
-      #     pip install -U pylint
-      #     python -m pylint --limit-inference-results=1 --rcfile=.pylintrc relstorage -f parseable -r n
+      - name: lint
+        if: matrix.python-version == '3.11' && startsWith(runner.os, 'Linux')
+        # At this writing, PyLint 2.17/astroid 2.15 won't work on 3.12
+        run: |
+          pip install -U pylint
+          python -m pylint --limit-inference-results=1 --rcfile=.pylintrc relstorage -f parseable -r n
       - name: Initialize Test Databases
         if: startsWith(runner.os, 'macOS')
         run: |

.pylintrc

@@ -120,7 +120,7 @@ init-hook =
 # readable, thing
 # unnecessary-lambda-assignment: We use this pattern a fair amount
 # redefined-variable-type: Fairly common
-
+# compare-to-zero: Often makes things less readable; an explicit == 0 can be better than 'not foo'
 disable=wrong-import-position,
     wrong-import-order,
     missing-docstring,
@@ -140,6 +140,9 @@ disable=wrong-import-position,
     unnecessary-lambda-assignment,
     redefined-variable-type,
     cyclic-import,
+    compare-to-zero,
+    missing-param-doc,
+    missing-type-doc,
 
 enable=consider-using-augmented-assign
 
@@ -195,9 +198,12 @@ max-complexity=11
 # pylint leaves it off. This is the proximal cause of the
 # undefined-all-variable crash.
 unsafe-load-any-extension = yes
+extension-pkg-allow-list = relstorage.cache._objectindex,relstorage.cache.cache,relstorage._inthashmap
 # This does not seem to work, hence the init-hook
 property-classes=zope.cachedescriptors.property.Lazy,zope.cachedescriptors.property.Cached
 
+
+
 [CLASSES]
 # List of interface methods to ignore, separated by a comma. This is used for
 # instance to not check methods defines in Zope's Interface base class.

src/relstorage/_util.py

@@ -427,7 +427,7 @@ def byte_display(size):
     """
     Returns a string with the correct unit (KB, MB), given the size in bytes.
     """
-    if size == 0:
+    if not size:
         return '0 KB'
     if size <= 1024:
         return '%s bytes' % size
@@ -531,7 +531,7 @@ def __getattr__(self, name):
     def __setattr__(self, name, value):
         if name in CloseTracker.__slots__:
             object.__setattr__(self, name, value)
-            return
+            return None
         return setattr(self._tracked, name, value)
 
     def close(self):
@@ -573,7 +573,7 @@ class NeedsFetchallBeforeCloseCursor(CloseTrackerCursor): # pragma: no cover
     def close(self):
         if self.needs_fetchall:
             raise AssertionError("Forgot to fetchall")
-        super(NeedsFetchallBeforeCloseCursor, self).close()
+        super().close()
 
     def execute(self, stmt, args=None):
         if self.needs_fetchall:

src/relstorage/adapters/_util.py

@@ -66,7 +66,7 @@ def prop(inst):
             raise query
 
         if extension:
-            query = query + extension
+            query += extension
         if formatted:
             query = intern(query % inst.runner.script_vars)
 

src/relstorage/adapters/adapter.py

@@ -208,6 +208,7 @@ def lock_objects_and_detect_conflicts(self, cursor, read_current_oids):
                 self._describe_best_lock_objects_and_detect_conflicts(),
                 kind
             )
+            return None # unreachable
 
     def _composed_lock_objects_and_detect_conflicts(self, cursor, read_current_oids):
         read_current_oid_ints = read_current_oids.keys()

src/relstorage/adapters/connmanager.py

@@ -58,7 +58,7 @@ def _connection_callback_open_args(connmanager, callback):
     read_only = getattr(callback, 'transaction_read_only', None)
     deferrable = getattr(callback, 'transaction_deferrable', None)
     application_name = getattr(callback, 'transaction_application_name', None)
-    return dict(
+    return dict( # pylint:disable=use-dict-literal
         isolation=isolation or connmanager.isolation_store,
         read_only=read_only or False,
         deferrable=deferrable or False,
@@ -73,6 +73,7 @@ class AbstractConnectionManager(object):
 
     Responsible for opening and closing database connections.
     """
+    # pylint:disable=too-many-instance-attributes
 
     # a series of callables (cursor, restart=bool)
     # for when a store connection is opened.

src/relstorage/adapters/drivers.py

@@ -152,7 +152,7 @@ def __init__(self):
                 "or the driver was set to 'auto', there may be more drivers to attempt.",
                 self.__name__, self.MODULE_NAME,
                 exc_info=True)
-            raise DriverNotImportableError(self.__name__, reason=str(ex))
+            raise DriverNotImportableError(self.__name__, reason=str(ex)) from ex
 
 
         self.disconnected_exceptions = (mod.OperationalError,
@@ -196,12 +196,12 @@ def _sockets_gevent_monkey_patched(self):
             from gevent import monkey
         except ImportError: # pragma: no cover
             return False
-        else:
-            # some versions of gevent have a bug where if we're monkey-patched
-            # on the command line using python -m gevent.monkey /path/to/testrunner ...
-            # it doesn't report being monkey-patched.
-            import socket
-            return monkey.is_module_patched('socket') or 'gevent' in repr(socket.socket)
+
+        # some versions of gevent have a bug where if we're monkey-patched
+        # on the command line using python -m gevent.monkey /path/to/testrunner ...
+        # it doesn't report being monkey-patched.
+        import socket
+        return monkey.is_module_patched('socket') or 'gevent' in repr(socket.socket)
 
     # Common compatibility shims, overriden as needed.
 
@@ -404,7 +404,7 @@ class _NoGeventConnectionMixin(object):
     gevent_write_watcher = None
     gevent_sleep = None
 
-try:
+try: # pylint:disable=too-complex
     import gevent
 except ImportError:
     GeventDriverMixin = _NoGeventDriverMixin
@@ -488,7 +488,7 @@ class GeventConnectionMixin(_NoGeventConnectionMixin):
 
         def close(self):
             self.__close_watchers()
-            super(GeventConnectionMixin, self).close()
+            super().close()
 
         def __check_watchers(self):
             # We can be used from more than one thread in a sequential

src/relstorage/adapters/interfaces.py

@@ -59,34 +59,34 @@ class IDBDriver(Interface):
     __name__ = Attribute("The name of this driver")
 
     disconnected_exceptions = Tuple(
-        description=(u"A tuple of exceptions this driver can raise on any operation if it is "
-                     u"disconnected from the database."),
+        description=("A tuple of exceptions this driver can raise on any operation if it is "
+                     "disconnected from the database."),
         value_type=Factory(IException)
     )
 
     close_exceptions = Tuple(
-        description=(u"A tuple of exceptions that we can ignore when we try to "
-                     u"close the connection to the database. Often this is the same "
-                     u"or an extension of `disconnected_exceptions`."
-                     u"These exceptions may also be ignored on rolling back the connection, "
-                     u"if we are otherwise completely done with it and prepared to drop it. "),
+        description=("A tuple of exceptions that we can ignore when we try to "
+                     "close the connection to the database. Often this is the same "
+                     "or an extension of `disconnected_exceptions`."
+                     "These exceptions may also be ignored on rolling back the connection, "
+                     "if we are otherwise completely done with it and prepared to drop it. "),
         value_type=Factory(IException),
     )
 
     lock_exceptions = Tuple(
-        description=u"A tuple of exceptions",
+        description="A tuple of exceptions",
         value_type=Factory(IException),
     ) # XXX: Document
 
     use_replica_exceptions = Tuple(
-        description=(u"A tuple of exceptions raised by connecting "
-                     u"that should cause us to try a replica."),
+        description=("A tuple of exceptions raised by connecting "
+                     "that should cause us to try a replica."),
         value_type=Factory(IException)
     )
 
     Binary = Attribute("A callable.")
 
-    dialect = Object(IDBDialect, description=u"The IDBDialect for this driver.")
+    dialect = Object(IDBDialect, description="The IDBDialect for this driver.")
 
     cursor_arraysize = Attribute(
         "The value to assign to each new cursor's ``arraysize`` attribute.")
@@ -252,7 +252,7 @@ class DriverNotAvailableError(Exception):
     reason = None
 
     def __init__(self, driver_name, driver_options=None, reason=None):
-        super(DriverNotAvailableError, self).__init__(driver_name)
+        super().__init__(driver_name)
         self.driver_name = driver_name
         self.driver_options = driver_options
         self.reason = reason
@@ -304,7 +304,7 @@ class NoDriversAvailableError(DriverNotAvailableError):
     """
 
     def __init__(self, driver_name='auto', driver_options=None, reason=None):
-        super(NoDriversAvailableError, self).__init__(driver_name, driver_options, reason)
+        super().__init__(driver_name, driver_options, reason)
 
 
 class IDBDriverOptions(Interface):
@@ -574,11 +574,6 @@ def __bool__():
         Return true if the database connection is believed to be ready to use.
         """
 
-    def __nonzero__():
-        """
-        Same as __bool__ for Python 2.
-        """
-
     def drop():
         """
         Unconditionally drop (close) the database connection.
@@ -1248,7 +1243,7 @@ class IRelStorageAdapter(Interface):
     driver = Object(IDBDriver)
     connmanager = Object(IConnectionManager)
     dbiter = Object(IDatabaseIterator)
-    keep_history = Bool(description=u"True if this adapter supports undo")
+    keep_history = Bool(description="True if this adapter supports undo")
     locker = Object(ILocker)
     mover = Object(IObjectMover)
     oidallocator = Object(IOIDAllocator)

src/relstorage/adapters/mover.py

@@ -197,8 +197,7 @@ def get_object_tid_after(self, cursor, oid, tid):
         """
         self._get_tid_after_query.execute(cursor, (oid, tid))
         row = cursor.fetchone()
-        if row:
-            return row[0]
+        return row[0] if row else None
 
     _current_object_tids_queries = (
         (('zoid', 'tid'), 'current_object', 'zoid'),
@@ -354,20 +353,19 @@ def _generic_restore(self, batcher, oid, tid, data,
                 command=command,
                 suffix=suffix
             )
-        else:
+        elif data:
             # history free can only delete the entire record.
-            if data:
-                batcher.insert_into(
-                    "object_state (zoid, tid, state_size, state)",
-                    "%s, %s, %s, %s",
-                    (oid, tid, size, encoded),
-                    rowkey=oid,
-                    size=size,
-                    command=command,
-                    suffix=suffix
-                )
-            else:
-                batcher.delete_from('object_state', zoid=oid)
+            batcher.insert_into(
+                "object_state (zoid, tid, state_size, state)",
+                "%s, %s, %s, %s",
+                (oid, tid, size, encoded),
+                rowkey=oid,
+                size=size,
+                command=command,
+                suffix=suffix
+            )
+        else:
+            batcher.delete_from('object_state', zoid=oid)
 
     def restore(self, cursor, batcher, oid, tid, data):
         raise NotImplementedError()
@@ -574,7 +572,7 @@ def download_blob(self, cursor, oid, tid, filename):
                     break
 
                 if f is None:
-                    f = open(filename, 'wb')
+                    f = open(filename, 'wb') # pylint:disable=consider-using-with
 
                 f.write(chunk)
                 bytecount += len(chunk)

src/relstorage/adapters/mysql/adapter.py

@@ -106,7 +106,7 @@ def __init__(self, options=None, oidallocator=None,
         self.connmanager = connmanager
         self.locker = locker
         self.mover = mover
-        super(MySQLAdapter, self).__init__(options)
+        super().__init__(options)
 
     def _create(self):
         options = self.options
@@ -233,7 +233,7 @@ def lock_database_and_choose_next_tid(self,
         args = ()
         if self.keep_history:
             # (packed, username, descr, extension)
-            proc = proc + '(%s, %s, %s, %s)'
+            proc += '(%s, %s, %s, %s)'
             args = (False, username, description, extension)
 
         multi_results = self.driver.callproc_multi_result(cursor, proc, args)
@@ -252,7 +252,7 @@ def lock_database_and_move(self,
         if not self.version_detector.supports_good_stored_procs(store_connection.cursor):
             # XXX: When can we drop this? Probably not until AppVeyor upgrades
             # MySQL past 5.7.12.
-            return super(MySQLAdapter, self).lock_database_and_move(
+            return super().lock_database_and_move(
                 store_connection, load_connection,
                 transaction_has_blobs,
                 ude,

src/relstorage/adapters/mysql/connmanager.py

@@ -50,7 +50,7 @@ def __init__(self, driver, params, options):
         self._params = params.copy()
         self._db_connect = driver.connect
         self._db_driver = driver
-        super(MySQLdbConnectionManager, self).__init__(options, driver)
+        super().__init__(options, driver)
 
         self.isolation_load = self.isolation_repeatable_read_ro
         self.isolation_store = self.isolation_read_committed

src/relstorage/adapters/mysql/drivers/__init__.py

@@ -35,7 +35,7 @@ def can_prepare(self):
         # If there are params, we can't prepare unless we're using
         # the binary protocol; otherwise we have to SET user variables
         # with extra round trips, which is worse.
-        return not self.placeholders and super(MySQLCompiler, self).can_prepare()
+        return not self.placeholders and super().can_prepare()
 
     _PREPARED_CONJUNCTION = 'FROM'
 
@@ -142,7 +142,7 @@ class AbstractMySQLDriver(AbstractModuleDriver):
     _init_command = ''
 
     def __init__(self):
-        super(AbstractMySQLDriver, self).__init__()
+        super().__init__()
 
         kv = ["%s=%s" % (k, v) for k, v in self.MY_SESSION_VARS.items()]
         self._init_command = "SET " + ", ".join(kv)
@@ -156,13 +156,13 @@ def cursor(self, conn, server_side=False):
             cursor = conn.cursor(self._server_side_cursor)
             cursor.arraysize = self.cursor_arraysize
         else:
-            cursor = super(AbstractMySQLDriver, self).cursor(conn, server_side=False)
+            cursor = super().cursor(conn, server_side=False)
         return cursor
 
     def connect(self, *args, **kwargs):
         if self._init_command:
             kwargs['init_command'] = self._init_command
-        return super(AbstractMySQLDriver, self).connect(*args, **kwargs)
+        return super().connect(*args, **kwargs)
 
     def synchronize_cursor_for_rollback(self, cursor):
         """Does nothing."""