code: def createEditor(self, parent, option, index):
          
          combo = QtGui.QComboBox(parent)
          combo.addItems(SupportedDtypes.names())
          combo.currentIndexChanged.connect(self.currentIndexChanged)
          return combo
docs: Creates an Editor Widget for the given index.
  
          Enables the user to manipulate the displayed data in place. An editor
          is created, which performs the change.
          The widget used will be a `QComboBox` with all available datatypes in the
          `pandas` project.
  
          Args:
              parent (QtCore.QWidget): Defines the parent for the created editor.
              option (QtGui.QStyleOptionViewItem): contains all the information
                  that QStyle functions need to draw the items.
              index (QtCore.QModelIndex): The item/index which shall be edited.
  
          Returns:
              QtGui.QWidget: he widget used to edit the item specified by index
                  for editing.