title: PyGtk - set checkbox in the treeview of a specific row invisible
body: <p>I would like to make the checkbox in the node "parent 1" and "child 1 of parent 1" invisible. Do you know how to solve this issue?
  I am still struggling with the modifying cell renderers for a specific row and not for the entire column.</p>
  
  <p><a href="https://i.stack.imgur.com/Z7vVo.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Z7vVo.png" alt="enter image description here"></a></p>
  
  <p>This is the code:</p>
  
  <pre><code>#!/usr/bin/env python
  
  # example basictreeview.py
  
  import pygtk
  pygtk.require('2.0')
  import gtk
  
  class BasicTreeViewExample:
      # close the window and quit
      def delete_event(self, widget, event, data=None):
          gtk.main_quit()
          return False
  
      def __init__(self):
          # Create a new window
          self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
  
          self.window.set_title("Basic TreeView Example")
  
          self.window.set_size_request(200, 200)
  
          self.window.connect("delete_event", self.delete_event)
  
          # create a TreeStore with one string column to use as the model
          self.treestore = gtk.TreeStore(str)
  
          # we'll add some data now - 4 rows with 3 child rows each
          for parent in range(4):
              piter = self.treestore.append(None, ['parent %i' % parent])
              for child in range(3):
                  self.treestore.append(piter, ['child %i of parent %i' %
                                                (child, parent)])
  
          # create the TreeView using treestore
          self.treeview = gtk.TreeView(self.treestore)
  
          # create the TreeViewColumn to display the data
          self.tvcolumn = gtk.TreeViewColumn('Column 0')
  
          # add tvcolumn to treeview
          self.treeview.append_column(self.tvcolumn)
  
          # create a CellRendererText to render the data
          self.cell = gtk.CellRendererText()
          self.cell1 = gtk.CellRendererToggle()
  
          # add the cell to the tvcolumn and allow it to expand
          self.tvcolumn.pack_start(self.cell, True)
          self.tvcolumn.pack_start(self.cell1, True)
          # set the cell "text" attribute to column 0 - retrieve text
          # from that column in treestore
          self.tvcolumn.add_attribute(self.cell, 'text', 0)
  
          # make it searchable
          self.treeview.set_search_column(0)
  
          # Allow sorting on the column
          self.tvcolumn.set_sort_column_id(0)
  
          # Allow drag and drop reordering of rows
          self.treeview.set_reorderable(True)
  
          swH = gtk.ScrolledWindow()
          swH.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_AUTOMATIC)
          swH.add(self.treeview)
          self.window.add(swH)
  
          self.window.show_all()
  
  def main():
      gtk.main()
  
  if __name__ == "__main__":
      tvexample = BasicTreeViewExample()
      main()
  </code></pre>
  
  <p>I hope you can help me.</p>