title: Copy items from treeview tkinter
body: <p>I have a tree view in one of my tkinter app and i wanted to know if it really is possible to actually, just copy a selected field on right-clicking by the user. If not , is there any other widget tht allows the user to copy a selected field shown in GUI window.</p>
  <p>Code:</p>
  <pre><code>    log = Toplevel(root)
      log.title('View all Visitors')
      log.focus_force()
      # setup treeview
      columns = (('ID', 80), ('S_ID', 80), ('S_NAME', 300), ('Title of the book', 500), ('Accession no. of 
                  book', 80),
                 ('Date Taken', 100), ('Due Date', 100), ('Date_Returned', 100), ('Status', 80))
      tree = ttk.Treeview(log, height=20, columns=[
                          x[0] for x in columns], show='headings')
      tree.grid(row=0, column=0, sticky='news')
  
      # setup columns attributes
      for col, width in columns:
          tree.heading(col, text=col)
          tree.column(col, width=width, anchor=tk.CENTER)
  
      # fetch data
      con = mysql.connect(host='localhost', user='root',
                          password='monkey123', database='library')
      c = con.cursor()
      sql_command_1 = 'SELECT * FROM borrow;'
      c.execute(sql_command_1)
  
      # populate data to treeview
      for rec in c:
          tree.insert('', 'end', value=rec)
  
      # scrollbar
      sb = tk.Scrollbar(log, orient=tk.VERTICAL, command=tree.yview)
      sb.grid(row=0, column=1, sticky='ns')
      tree.config(yscrollcommand=sb.set)
      a = tree.item(tree.focus())['values']
  
      btn = tk.Button(log, text='Close', command=out,
                      width=20, bd=2, fg='red',font=font_text)
      btn.grid(row=2, column=0, columnspan=2, sticky=E+W)
  </code></pre>
  <p>Thanks in advance :)</p>