Tkinter how to distinguish between <Key> and <Control-Key> bindings?

Question

This might be a simple answer.

I have a text widget which i want to bind any alphanumeric keyboard key (a-zA-Z0-9_ and rest of regular keys) to a specific method, and Ctrl+F to another method.

Using widget.bind("<Key>", method) will create the following:

1. Click Ctrl+F will invoke method twice, one for Ctrl (event.keysym = Control_L, event.char = None) and second for F (event.keysym = f, event.char = <invalid>)
2. Click F will invoke method (event.keysym = f, event.char = f)

Is there a way to distinguish between the two scenarios?

Answer 1

You can bind <Control-f> and <f> (and the same with other keys).

import tkinter as tk

# --- functions ---

def key_f(event):
    print('key: f')

def key_shift_f(event):
    print('key: Shift + f')

def key_control_f(event):
    print('key: Control + f')

def key_control_shift_f(event):
    print('key: Control+Shift + f')

# --- main ---

root = tk.Tk()

#root.bind("<f>", key_f) # it works too
#root.bind("<F>", key_shift_f) # it works too
root.bind("f", key_f)
root.bind("F", key_shift_f)
root.bind("<Control-f>", key_control_f)
root.bind("<Control-F>", key_control_shift_f)

root.mainloop()

Or you can use event.state & 4 to recognize key with Control.

You need bit-wise & because it keeps information about other special keys

(see Masks/Modifier on http://infohost.nmt.edu/tcc/help/pubs/tkinter/web/event-handlers.html)

import tkinter as tk

# --- functions ---

def method(event):
    print('-----')
    print('[DEBUG] event.char  :', event.char)
    print('[DEBUG] event.keysym:', event.keysym)
    print('[DEBUG] event.state :', event.state, '=', bin(event.state))

    if event.char: # skip Control_L, etc.

        # if you need `& 5` then it has to be before `& 4` 

        if event.state & 5 == 5: # it needs `== 5` because `& 5` can give results `5`, `4` or `1` which give `True` or `0` which gives `False`
            print('method: Control+Shift +', event.keysym)

        elif event.state & 4: # it doesn't need `== 4` because `& 4` can give only results `4` or `0`
            print('method: Control +', event.keysym)

        elif event.state & 1: # it doesn't need `== 1` because `& 1` can give only results `1` or `0`
            print('method: Shift +', event.keysym)

        else:
            print('method:', event.keysym)

# --- main ---

root = tk.Tk()

root.bind("<Key>", method)

root.mainloop()