Status of shift and caps lock in Python

Keyboard events in Tkinter can be tricky.

I suggest you have a look at the following, in order:

• http://effbot.org/tkinterbook/tkinter-events-and-bindings.htm
• http://infohost.nmt.edu/tcc/help/pubs/tkinter/events.html (read the whole chapter on events)
• http://www.faqts.com/knowledge_base/view.phtml/aid/4281

Here is a program that displays the value of the keycode and state event parameters. You can use this to experiment. Click in the window, then hit the keyboard.

from Tkinter import *
root = Tk()

def key(event):
    print "Keycode:", event.keycode, "State:", event.state

def callback(event):
    frame.focus_set()
    print "clicked at", event.x, event.y

frame = Frame(root, width=100, height=100)
frame.bind("<Key>", key)
frame.bind("<Button-1>", callback)
frame.pack()

root.mainloop()

Lock and Shift event modifiers:

http://infohost.nmt.edu/tcc/help/pubs/tkinter/event-modifiers.html

I googled and got one.. I am not sure whether it works for you for all keys...

http://www.java2s.com/Code/Python/Event/KeyactionFunctionKeyALtControlShift.htm

Use:

from Tkinter import *
root = Tk()
caps_lock_on = False
def CAPSLOCK_STATE():
    import ctypes
    hllDll = ctypes.WinDLL ("User32.dll")
    VK_CAPITAL = 0x14
    return hllDll.GetKeyState(VK_CAPITAL)

CAPSLOCK = CAPSLOCK_STATE()
if ((CAPSLOCK) & 0xffff) != 0:
    print "\nCaps lock is on\n"
    caps_key_on = True
else:
    caps_key_on = False
    print 'Caps lock is off'

def caps_lock_pressed(event=''):
    global caps_lock_on
    if caps_lock_on == False:
        caps_lock_on = True
        print 'Caps lock is on'
    else:
        caps_lock_on = False
        print 'Caps lock is off'

#Changes if shift key is on and off 
def shift_key_pressed(event=''):
    global shift_key_on
    shift_key_on = True
    print 'Shift is being holded' 

def shift_key_released(event=''):
    global shift_key_on
    shift_key_on = False
    print 'Shift has been released'
        
root.bind('<Caps_Lock>',caps_lock_pressed)
root.bind('<Shift_L>',shift_key_pressed)
root.bind('<Shift_R>',shift_key_pressed)
root.bind('<KeyRelease-Shift_R>',shift_key_released)
root.bind('<KeyRelease-Shift_L>',shift_key_released)
root.mainloop()

This will check if its caps lock, and then it will bind caps lock and shift to change the state. The caps lock detecting system is borrowed.