code: def keypress_event(self, event):
      if not self.is_active():
          return None
      keysym = event.keysym
      if hasattr(event, "mc_state"):
          state = event.mc_state
      else:
          state = 0
      if keysym != "Tab":
          self.lastkey_was_tab = False
      if (
          len(keysym) == 1
          or keysym in ("underscore", "BackSpace")
          or (self.mode == FILES and keysym in ("period", "minus"))
      ) and not (state & ~MC_SHIFT):
          # Normal editing of text
          if len(keysym) == 1:
              self._change_start(self.start + keysym)
          elif keysym == "underscore":
              self._change_start(self.start + "_")
          elif keysym == "period":
              self._change_start(self.start + ".")
          elif keysym == "minus":
              self._change_start(self.start + "-")
          else:
              # keysym == "BackSpace"
              if len(self.start) == 0:
                  self.hide_window()
                  return None
              self._change_start(self.start[:-1])
          self.lasttypedstart = self.start
          self.listbox.select_clear(
              0, int(self.listbox.curselection()[0])
          )
          self.listbox.select_set(self._binary_search(self.start))
          self._selection_changed()
          return "break"
  
      elif keysym == "Return":
          self.complete()
          self.hide_window()
          return "break"
  
      elif (
          (
              self.mode == ATTRS
              and keysym
              in (
                  "period",
                  "space",
                  "parenleft",
                  "parenright",
                  "bracketleft",
                  "bracketright",
              )
          )
          or (
              self.mode == FILES
              and keysym
              in ("slash", "backslash", "quotedbl", "apostrophe")
          )
          and not (state & ~MC_SHIFT)
      ):
          # If start is a prefix of the selection, but is not '' when
          # completing file names, put the whole
          # selected completion. Anyway, close the list.
          cursel = int(self.listbox.curselection()[0])
          if self.completions[cursel][
              : len(self.start)
          ] == self.start and (self.mode == ATTRS or self.start):
              self._change_start(self.completions[cursel])
          self.hide_window()
          return None
  
      elif (
          keysym in ("Home", "End", "Prior", "Next", "Up", "Down")
          and not state
      ):
          # Move the selection in the listbox
          self.userwantswindow = True
          cursel = int(self.listbox.curselection()[0])
          if keysym == "Home":
              newsel = 0
          elif keysym == "End":
              newsel = len(self.completions) - 1
          elif keysym in ("Prior", "Next"):
              jump = self.listbox.nearest(
                  self.listbox.winfo_height()
              ) - self.listbox.nearest(0)
              if keysym == "Prior":
                  newsel = max(0, cursel - jump)
              else:
                  assert keysym == "Next"
                  newsel = min(len(self.completions) - 1, cursel + jump)
          elif keysym == "Up":
              newsel = max(0, cursel - 1)
          else:
              assert keysym == "Down"
              newsel = min(len(self.completions) - 1, cursel + 1)
          self.listbox.select_clear(cursel)
          self.listbox.select_set(newsel)
          self._selection_changed()
          self._change_start(self.completions[newsel])
          return "break"
  
      elif keysym == "Tab" and not state:
          if self.lastkey_was_tab:
              # two tabs in a row; insert current selection and close acw
              cursel = int(self.listbox.curselection()[0])
              self._change_start(self.completions[cursel])
              self.hide_window()
              return "break"
          else:
              # first tab; let AutoComplete handle the completion
              self.userwantswindow = True
              self.lastkey_was_tab = True
              return None
  
      elif any(
          s in keysym
          for s in (
              "Shift",
              "Control",
              "Alt",
              "Meta",
              "Command",
              "Option",
          )
      ):
          # A modifier key, so ignore
          return None
  
      elif event.char and event.char >= " ":
          # Regular character with a non-length-1 keycode
          self._change_start(self.start + event.char)
          self.lasttypedstart = self.start
          self.listbox.select_clear(
              0, int(self.listbox.curselection()[0])
          )
          self.listbox.select_set(self._binary_search(self.start))
          self._selection_changed()
          return "break"
  
      else:
          # Unknown event, close the window and let it through.
          self.hide_window()
          return None
  
imports: import platform
  from tkinter import *
  from tkinter.ttk import Scrollbar
  from idlelib.autocomplete import FILES, ATTRS
  from idlelib.multicall import MC_SHIFT
label_desc: Use image node_id 12 for calling the AutoCompleteWindow obj's underlying member method code with example usage: obj.keypress_event(event) and returns: None, str, str, None, str, None, str, None, None, str, None