python 3.x - Need to call class method from different class without initialization of the first class or some other way around it -

i have small problem code.

there 2 classes. first 1 creates window options button. upon clicking button, second class called , creates window ok button. let's there checkbox, changes background color black or that. after clicking button, whatever changes made in options stored file , second window closed.

all of works fine. problem need call method update_init first class apply changes mainwindow. code below shows first solution problem, understand, using second mainloop create second thread, should avoided.

class mainwindow:      def __init__(self, master):         self.master = master         self.options_btn = tk.button(self.master, text="options", command=self.open_options)         self.options_btn.pack()         self.options_window = none      def open_options(self):         options_master = tk.toplevel()         self.options_window = optionswindow(options_master)         options_master.mainloop()         lst = meta_load()   # loads changes file         self.update_init(lst)      def update_init(self, lst):         #code   class optionswindow:      def __init__(self, master):         self.master = master         self.ok_btn = tk.button(self.master, text="ok", command=self.update_meta)         self.ok_btn.pack()      def update_meta(self):         meta_save(12)  # saves changes file         self.master.destroy()  main_master = tk.tk() main_master.minsize(width=1280, height=720) b = mainwindow(main_master) main_master.mainloop() 

my second solution put both classes one, code quite messy if so. can somehow call method update_init (which in mainwindow class) optionswindow class without initializing new mainwindow class window? or there other way deal this? appreciate help.

i sorry if specific, i've tried make general possible, it's specific problem , couldn't find information anywhere on internet.

in general can call class method anywhere want , pass without initialisation of class's instance, objective nature of python, beware of self dependencies! although, don't think that's practice.

class a:     def __init__(self):         self.foo = 'foo'      def return_foo(self):         return self.foo   class b:     def __init__(self):         self.bar = 'bar'         print('ha-ha im inited!')      def return_bar(self):         try:             return self.bar         except attributeerror:             return 'bar'   def test():     = a()     # b = b()     return_bar = getattr(b, 'return_bar', none)     if callable(return_bar):         print('%s%s' % (a.return_foo(), return_bar(none)))   test() 

links:

• getattr
• callable