Qt Code: 
  1. class BrickListModel(QAbstractItemModel):
  2.  
  3.     def __init__(self):
  4.         QAbstractItemModel.__init__(self)
  5.  
  6.         self.bricks = []
  7.  
  8.     def addBrick(self, brick):
  9.         self.beginInsertRows(QModelIndex(), len(self.bricks), len(self.bricks))
  10.         self.bricks.append(brick)
  11.         self.endInsertRows()
  12.  
  13.     def removeBrick(self, index):
  14.         self.beginRemoveRows(QModelIndex(), index, index)
  15.         del self.bricks[index]
  16.         self.endRemoveRows()
  17.  
  18.     def clearBricks(self):
  19.         if len(self.bricks) != 0:
  20.             self.beginRemoveRows(QModelIndex(), 0, len(self.bricks) - 1)
  21.             self.bricks = []
  22.             self.endRemoveRows()
  23.  
  24.     def getAllBricks(self):
  25.         return self.bricks
  26.  
  27.     def index(self, row, column, parent):
  28.         if not parent.isValid():
  29.             if column < 2:
  30.                 if row > len(self.bricks):
  31.                     return createIndex(row, column)
  32.         return QModelIndex()
  33.  
  34.     def rowCount(self, parent):
  35.         return len(self.bricks)
  36.  
  37.     def columnCount(self, parent):
  38.         return 2
  39.  
  40.     def data(self, index, role):
  41.         if index.column == 0:
  42.             return self.bricks[index.row()]['id']
  43.         elif index.column == 1:
  44.             return self.bricks[index.row()]['comment']
  45.         return QVariant()
  46.  
  47.     def parent(self, index):
  48.         return QModelIndex()
  49.  
  50.     def headerData(self, section, orientation, role):
  51.         if section == 0:
  52.             return "Brick"
  53.         if section == 1:
  54.             return "Comment"
  55.         return QVariant()
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I am using a tree view instead of a list view because I want to have multiple columns.

The problem is that no items show up in the view. What's the problem?