Pyqt : QGraphicsView use addItem Error

When I would like to adda Line Item in the View
system send message
" ‘builtin_function_or_method’ object has no attribute ‘addItem’"
or ‘NoneType’ object has no attribute ‘addItem’
can you help me?

the following is the error line of my code
can I already check ‘start’ and ‘end’ is a position


Did you mean QGraphicsScene.addItem(......) ?