Python 按名称查找QTableWidget项的列/行

我试图找到

QtableWidget

的标题单元格的列，如下所示

column = QtCore.QObject.findChild(mytableWidget, unicode("NAME")).column() # it should retruns 0

其中

mytableWidget

是已定义的表

    self.mytableWidget = QtGui.QTableWidget(self.frame)
    ...
    ...
    item = QtGui.QTableWidgetItem("NAME")
    self.mytableWidget.setHorizontalHeaderItem(0, item) # searching this item

但是我得到了以下错误

TypeError: 'PySide.QtCore.QObject.findChild' called with wrong argument types:
  PySide.QtCore.QObject.findChild(unicode)
Supported signatures:
  PySide.QtCore.QObject.findChild(PyTypeObject, unicode = QString())