Script to view a file directory

Hello I am trying to write a script that will view the contents of a file directory in a UI pannel based on the object selected. Here is what I have so far:

import bpy

class booknotes(bpy.types.Panel):
    bl_label = "Book Notes"
    bl_idname = "booknotes"
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"

    def poll(self, context):
        if(bpy.context.active_object.type == 'MESH'):

    def draw(self, context):
        layout = self.layout

        obj = context.object

        row = layout.row()
        row.label(text="Available Notes!", icon='WORLD_DATA')

        row = layout.row()
        row.label(text="Active object is: " +
        row = layout.row()
        row.prop(obj, "name")

def register():

def unregister():

if __name__ == "__main__":

For this code, when an object is selected I want to view the contents of “”. I am making directories with the same name as the active objects name. I will be putting text files in these directories and I would like a list of these files to show up in the UI Pannel in a box. When i click on one of the list items, I would like it to open in the text editor. Thank you.