How to select and test if a QGraphicsItem has been selected in PyQt

How can I select a QGraphicsItem and test to see if it has been selected? My program allows the user to add items to the QGraphicsScene (by clicking from the toolbar and then adding it to the scene). When the user clicks from the toolbar it lets the user add as many graphical items as he or she wants to the scene. I want the user to be able to select an item that was added and be able to move it. How would I go about doing that? Down below is my code:

class Form(QtGui.QMainWindow, QtGui.QWidget):
def __init__(self):
super(Form, self).__init__()
self.ui = uic.loadUi('Form.ui')

self.ui.actionHost.triggered.connect(self.place_ho st)
self.ui.actionSwitch.triggered.connect(self.place_ switch)

self.scene = graphicsScene()
self.ui.view.setScene(self.scene)

def place_host(self):
global host_cs
global switch_cs
global connectLine_cs
host_cs = 1
switch_cs = 0
connectLine_cs = 0

def place_switch(self):
global host_cs
global switch_cs
global connectLine_cs
switch_cs = 1
host_cs = 0
connectLine_cs = 0

class graphicsScene(QtGui.QGraphicsScene, QtGui.QWidget):
def __init__(self, parent=None):
super(graphicsScene, self).__init__(parent)
self.setSceneRect(-180, -90, 360, 180)

def mouseReleaseEvent(self, event):

if host_cs == 1:
pixmap = QtGui.QPixmap("host.png")
host_pixItem = QtGui.QGraphicsPixmapItem(pixmap.scaled(30, 30, QtCore.Qt.KeepAspectRatio))
host_pixItem.setFlag(QtGui.QGraphicsPixmapItem.Ite mIsSelectable)
host_pixItem.setFlag(QtGui.QGraphicsPixmapItem.Ite mIsMovable)
self.addItem(host_pixItem)
host_pixItem.setPos(event.scenePos())
hostItem_list.append(host_pixItem)
self.update()

elif switch_cs == 1:
pixmap = QtGui.QPixmap("switch.png")
switch_pixItem = QtGui.QGraphicsPixmapItem(pixmap.scaled(30, 30, QtCore.Qt.KeepAspectRatio))
self.addItem(switch_pixItem)
switch_pixItem.setPos(event.scenePos())
switchItem_list.append(switch_pixItem)
self.update()