[Tkinter] tkinter freezes by clicking button

[Gribouillis]

The child process cannot find do_solve, probably because the if __name__ == '__main__' part is not executed in the child process. Try to refactor the code this way

# tksudo.py

import solvesudo

def do_solve(sudoku):
    status = solvesudo.wsolve(sudoku)
    return status, sudoku

if __name__ ==  '__main__':
    from tkinter import Tk, Frame, Entry, Label, Button, IntVar, StringVar, LEFT
    from tkinter import messagebox
    from tkcallasync import tk_call_async, MULTIPROCESSING

    disabled = False

    def execute_solver():
        global disabled
        if disabled:
            messagebox.showinfo("warning", "It's still calculating...")
            return

        def callback(result):
            global disabled
            disabled = False
            status, sudoku = result
            solvesudo.printSUDOKU(sudoku)
            result_var.set('Found!' if status else 'Not Found!')

        disabled = True
        tk_call_async(root, do_solve, args=(solvesudo.sudoku,), callback=callback, method=MULTIPROCESSING)

    root = Tk()

    row = Frame(root)
    row.pack()
    Button(row, text="Solve Sudoku", command =execute_solver).pack(side=LEFT)
    Button(row, text="It's responsive", command= lambda: messagebox.showinfo("info", "it's responsive")).pack(side=LEFT)

    result_var = StringVar()
    Label(root, textvariable=result_var).pack()

    root.mainloop()