Question

我正在尝试使用Dunn重构的菜单代码但总是遇到问题。这是代码：

#!/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()

这是错误：

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)

我已经在脑子里按照这个代码几十次了，我无法弄清楚出了什么问题。我在menuData对象中添加并删除括号无效。

Answer 1

问题出在Parenthesized forms：

带括号的表达式列表产生表达式列表产生的任何内容：如果列表包含至少一个逗号，则产生一个元组;否则，它会产生构成表达式列表的单个表达式。

另见这个例子：

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

添加逗号会创建一个元组：

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

您的第一个列表项为：

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

所以你的代码需要一个可迭代的，但是当逗号丢失时，它开始迭代字符串值"&Quit\tCtrl+Q"（14个字符）。在指示位置添加逗号会创建一个元组并修复代码。

createMenuItem（）最多需要6个参数（给定14个）

1 个答案: