createMenuItem() takes at most 6 arguments (14 given)

Question

I am trying to use Dunn's refactored Menubar code but always run into problems with it. Here's the code:

#!/usr/bin/env python

import wx

class Darkscreen(wx.Frame):

    def __init__(self, parent, id):
        style = wx.DEFAULT_FRAME_STYLE
        wx.Frame.__init__(self, parent, id, 'Darkscreen10b1', size=(340, 200), style=style)
        panel = wx.Panel(self, -1)
        panel.SetBackgroundColour("Black")
        self.Bind(wx.EVT_CLOSE, self.OnCloseWindow)
        self.createMenuBar()
        self.Centre()

    def menuData(self):
        return [("&File", (
                    ("&Quit\tCtrl+Q", "Quit", self.OnCloseWindow))),
                ("&Color", (
                    ("&Black", "", self.OnBlack, wx.ITEM_RADIO),
                    ("&White", "", self.OnWhite, wx.ITEM_RADIO),
                    ("&Red", "", self.OnRed, wx.ITEM_RADIO),
                    ("&Green", "", self.OnGreen, wx.ITEM_RADIO),
                    ("&Blue", "", self.OnBlue, wx.ITEM_RADIO)))]

    def createMenuBar(self):
        menuBar = wx.MenuBar()
        for eachMenuData in self.menuData():
            menuLabel = eachMenuData[0]
            menuItems = eachMenuData[1]
            menuBar.Append(self.createMenu(menuItems), menuLabel)
        self.SetMenuBar(menuBar)

    def createMenu(self, menuData):
        menu = wx.Menu()
        for eachItem in menuData:
            if len(eachItem) == 2:
                label = eachItem[0]
                subMenu = self.createMenu(eachItem[1])
                menu.AppendMenu(wx.NewId(), label, subMenu)
            else:
                self.createMenuItem(menu, *eachItem)
        return menu

    def createMenuItem(self, menu, label, status, handler, kind=wx.ITEM_NORMAL):
        if not label:
            menu.AppendSeparator()
            return
        menuItem = menu.Append(-1, label, status, kind)
        self.Bind(wx.EVT_MENU, handler, menuItem)

    def OnBlack(self, event):
        panel.SetBackgroundColour("Black")
    def OnWhite(self, event):
        panel.SetBackgroundColour("White")
    def OnRed(self, event):
        panel.SetBackgroundColour("Red")
    def OnGreen(self, event):
        panel.SetBackgroundColour("Green")
    def OnBlue(self, event):
        panel.SetBackgroundColour("Blue")
    def OnCloseWindow(self, event):
        self.Destroy()

if __name__ == '__main__':
    app = wx.App(redirect=True, filename="dserr.txt")
    frame = Darkscreen(parent=None, id=-1)
    frame.Show()
    app.MainLoop()

Here's the error:

Traceback (most recent call last):
  File "L:\Rodney's\Development\Python\Working\darkscreen\darkscreen.py", line 67, in <module>
    frame = Darkscreen(parent=None, id=-1)
  File "L:\Rodney's\Development\Python\Working\darkscreen\darkscreen.py", line 13, in __init__
    self.createMenuBar()
  File "L:\Rodney's\Development\Python\Working\darkscreen\darkscreen.py", line 31, in createMenuBar
    menuBar.Append(self.createMenu(menuItems), menuLabel)
  File "L:\Rodney's\Development\Python\Working\darkscreen\darkscreen.py", line 42, in createMenu
    self.createMenuItem(menu, *eachItem)
TypeError: createMenuItem() takes at most 6 arguments (14 given)

I have followed this code in my head dozens of time and I cannot figure out what's wrong. I have added and taken away parentheses everwhere in the menuData object to no avail.

Answer 1

The issue is in Parenthesized forms:

A parenthesized expression list yields whatever that expression list yields: if the list contains at least one comma, it yields a tuple; otherwise, it yields the single expression that makes up the expression list.

See also this example:

>>> for x in ('hello'):  
...     print x
... 
h
e
l
l
o

Adding a comma creates a tuple:

>>> for x in ('hello',):
...     print x
... 
hello

Your first list item reads:

("&File", (("&Quit\tCtrl+Q", "Quit", self.OnCloseWindow) )
#                                                       ^-- no comma here

So your code expects an iterable, but as the comma is missing, it starts iterating over the string value "&Quit\tCtrl+Q" (14 characters). Adding a comma where indicated creates a tuple and fixes your code.