title: How can I update Entry without a "submit" button in Tkinter?
body: <p>So I have <code>Entries</code> which have some values assigned to them from a CFG File. I want to modify the CFG file when the <code>Entry</code> is updated, live, without a <code>submit</code> button; </p>
  
  <p>Using <code>&lt;Key&gt;</code> binding will work but will take only the previous value, not the current one, as the last key pressed is not taken into consideration as a value, but as a <code>key-press</code>.</p>
  
  <p>For example:</p>
  
  <pre><code>class EntryBox:
      def __init__(self, value, option, section, grid_row, master_e):
          self.section = section
          self.option = option
          self.box = Entry(master_e)
          self.box.grid(column=0, row=grid_row)
          self.serial_no = grid_row
          self.box.insert(0, value)
          self.box.bind("&lt;Key&gt;", lambda event: update_cfg(event, self, self.get_value()))
  
      def get_value(self):
          return self.box.get()
  
  
      def update_cfg(evt, entry_box,new_value):
          global config_file
          config_file.set(entry_box.section, entry_box.option, new_value)
          print "Config file modified. "+entry_box.section+" "+entry_box.option+" "+new_value
  </code></pre>
  
  <p>If the value in the <code>entry</code> is <code>05R</code> when I click on the <code>entry</code> and press 6, it will print <code>Config file modified. CURRENT_MEASUREMENT_EXAMPLE_HP shunt_resistance 05R</code>; after I press 7, it will print <code>Config file modified. CURRENT_MEASUREMENT_EXAMPLE_HP shunt_resistance 0R56</code> and so on, always with one keypress behind. The only way to live update it after the value has been changed is to press the <code>TAB</code> or <code>arrow</code> buttons. </p>