pylint: raise from

src/hand.py

@@ -140,8 +140,8 @@ class Hand(StrMixin):
                 if len(part) > 1:
                     try:
                         self.__lastSource = TileSource.byChar[part[1]]
-                    except KeyError:
-                        raise Exception('{} has unknown lastTile {}'.format(inString, part[1]))
+                    except KeyError as _:
+                        raise Exception('{} has unknown lastTile {}'.format(inString, part[1])) from _
                     if len(part) > 2:
                         self.__announcements = set(part[2])
             elif partId == 'L':

src/login.py

@@ -134,12 +134,11 @@ class Url(str, StrMixin):
                      '/modules/networkstatus',
                      'org.kde.Solid.Networking.status'],
                     stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate(timeout=1)
-            except subprocess.TimeoutExpired:
-                raise twisted.internet.error.ConnectError()
+            except subprocess.TimeoutExpired as _:
+                raise twisted.internet.error.ConnectError() from _
             stdoutdata = stdoutdata.strip()
             stderrdata = stderrdata.strip()
             if stderrdata == '' and stdoutdata != '4':
-                # pylint: disable=nonstandard-exception
                 raise twisted.internet.error.ConnectError()
             # if we have stderrdata, qdbus probably does not provide the
             # service we want, so ignore it

src/player.py

@@ -351,9 +351,9 @@ class Player(StrMixin):
         else:
             try:
                 self._concealedTiles.remove(tile)
-            except ValueError:
+            except ValueError as _:
                 raise Exception('removeTile(%s): tile not in concealed %s' %
-                                (tile, ''.join(self._concealedTiles)))
+                                (tile, ''.join(self._concealedTiles))) from _
         if tile is self.lastTile:
             self.lastTile = None
         self._hand = None

src/query.py

@@ -85,7 +85,7 @@ class DBCursor(sqlite3.Cursor):
             else:
                 if not failSilent:
                     logError(msg)
-                raise QueryException(msg)
+                raise QueryException(msg) from exc
             return
 
     def __str__(self):