Toplevel menus are displayed just under the title bar of the root or any other toplevel windows (or on Macintosh, along the upper edge of the screen). To create a toplevel menu, create a new Menu instance, and use add methods to add commands and other menu entries to it.
Example 31-1. Creating a toplevel menu
# File: menu-example-2.py
from Tkinter import *
root = Tk()
def hello():
print "hello!"
# create a toplevel menu
menubar = Menu(root)
menubar.add_command(label="Hello!", command=hello)
menubar.add_command(label="Quit!", command=root.quit)
# display the menu
root.config(menu=menubar)
mainloop()
Pulldown menus (and other submenus) are created in a similar fashion. The main difference is that they are attached to a parent menu (using add_cascade), instead of a toplevel window.
Example 31-2. Creating toplevel and pulldown menus
# File: menu-example-3.py
from Tkinter import *
root = Tk()
def hello():
print "hello!"
menubar = Menu(root)
# create a pulldown menu, and add it to the menu bar
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label="Open", command=hello)
filemenu.add_command(label="Save", command=hello)
filemenu.add_separator()
filemenu.add_command(label="Exit", command=root.quit)
menubar.add_cascade(label="File", menu=filemenu)
# create more pulldown menus
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(label="Cut", command=hello)
editmenu.add_command(label="Copy", command=hello)
editmenu.add_command(label="Paste", command=hello)
menubar.add_cascade(label="Edit", menu=editmenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label="About", command=hello)
menubar.add_cascade(label="Help", menu=helpmenu)
# display the menu
root.config(menu=menubar)
mainloop()
Finally, a popup menu is created in the same way, but is explicitly displayed, using the post method:
Example 31-3. Creating and displaying a popup menu
# File: menu-example-4.py
from Tkinter import *
root = Tk()
def hello():
print "hello!"
# create a popup menu
menu = Menu(root, tearoff=0)
menu.add_command(label="Undo", command=hello)
menu.add_command(label="Redo", command=hello)
# create a canvas
frame = Frame(root, width=512, height=512)
frame.pack()
def popup(event):
menu.post(event.x_root, event.y_root)
# attach popup to canvas
frame.bind("<Button-3>", popup)
mainloop()
You can use the postcommand callback to update (or even create) the menu everytime it is displayed.
Example 31-4. Updating a menu on the fly
# File: menu-example-5.py
from Tkinter import *
counter = 0
def update():
global counter
counter = counter + 1
menu.entryconfig(0, label=str(counter))
root = Tk()
menubar = Menu(root)
menu = Menu(menubar, tearoff=0, postcommand=update)
menu.add_command(label=str(counter))
menu.add_command(label="Exit", command=root.quit)
menubar.add_cascade(label="Test", menu=menu)
root.config(menu=menubar)
mainloop()