code: def create_grid(self, grid_width, grid_height):
          
          self.grid_layout = QGridLayout()
          self.setLayout(self.grid_layout)
          self.grid_layout.setSpacing(1)
          self.grid_wgs = {}
          for i in xrange(grid_height):
              for j in xrange(grid_width):
                  self.grid_wgs[(i, j)] = FieldWidget()
                  self.grid_layout.addWidget(self.grid_wgs[(i, j)], i, j)
docs: Create a grid layout with stacked widgets.
  
          Parameters
          ----------
          grid_width : int
              the width of the grid
          grid_height : int
              the height of the grid