Python: how to access a class's attribute from a module

You can achieve what you want by giving a reference of the Root instance as a parameter to your functions:

Instead of assigning to the Root class:

Root.status = Tkinter.StringVar()

Assign it to the Root instance:

self.status = Tkinter.StringVar()

There is no reason for assigning it to Root class instead of to the instance self, because its ownership is part of the Root instance as well: it is the components of the Root instance (the Tkinter parts) that fire the event to update.You could then give self as a parameter to your buttonevent:

def ok(self):    text_info(self.msglist.next())    buttonevent.do_event(self)    buttonevent.do_stuff(self)

And you can then make text_info part of your class:

class Root(object):    ...    def text_info(self, msg):        self.textinfo.configure(state='normal')        self.textinfo.insert(Tkinter.END, msg)        self.textinfo.see(Tkinter.END)

And change the buttonevent to this:

def do_event(root_instance):    # do something    root_instance.text_info(msg.next())

All "Root." changed as "self."main.py

# ~/main.pyimport Tkinterimport buttoneventfrom itertools import cyclecurwin=Nonemsglist = ['main_msg1\n', 'main_msg2\n', 'main_msg3\n', 'main_msg4\n']class Root(object):    def __init__(self, master):        self.msglist = cycle(msglist)        self.master = master        self.frame1 = Tkinter.Frame(master)        self.frame1.pack()        self.status = Tkinter.StringVar()        self.status_info = Tkinter.Label(self.frame1, textvariable=self.status)        self.status_info.pack()        self.status.set("Set by constructor")        self.curmsg='message 1\n'        self.frame2 = Tkinter.Frame(master)        self.frame2.pack()        self.textinfo = Tkinter.Text(self.frame2, width=20, height=10)        self.textinfo.insert(Tkinter.END, 'message 1\n')        self.textinfo.config(font='Arial')        self.textinfo.pack()        self.textinfo.config(bg=master.cget('bg'), relief=Tkinter.SUNKEN)        self.textinfo.configure(state='disabled')        self.frame3 = Tkinter.Frame(master)        self.frame3.pack()        self.button = Tkinter.Button(self.frame3, text='Ok', command=self.ok) # "Ok" function defined for click event        self.button.pack()    def ok(self):        #self.text_info(buttonevent.curmsg)        self.textinfo.configure(state='normal')        self.textinfo.insert(Tkinter.END, buttonevent.curmsg) # get message from buttonevent.py and set for window. Fisrst clicking will get initalized curmsg value. if you want get value after click write buttonevent.do_event() above this codes.        self.textinfo.see(Tkinter.END)        self.textinfo.configure(state='disabled')        buttonevent.do_event() # calling buttonevent's do_event function so it means global message will be changed. next click you will see new value for message.        buttonevent.do_stuff()if __name__ == '__main__':    root = Tkinter.Tk()    curwin=Root(root)    root.mainloop()

buttonevent.py

# ~/buttonevent.pyfrom itertools import cycleimport maindo_msg = ['do_msg1\n', 'do_msg2\n', 'do_msg3\n', 'do_msg4\n']msg = cycle(do_msg)curmsg=msg.next() # Add this variable to call main.py to first click eventdef do_event():    # do something    global curmsg #to edit variable value you must call it as global    curmsg=msg.next() #Changing variable value for each click    #Removed text_info function from main.py it is not necessary.def do_stuff():    # do something    print 'doing stuff'