tkinter python maximize window

If you want to set the fullscreen attribute to True, it is as easy as:

root = Tk()
root.attributes('-fullscreen', True)

However, it doesn't show the title bar. If you want to keep it visible, you can resize the Tk element with the geometry() method:

root = Tk()
w, h = root.winfo_screenwidth(), root.winfo_screenheight()
root.geometry("%dx%d+0+0" % (w, h))

With winfo_width() and winfo_height() you can get the width and height or the window, and also you can bind an event handler to the <Configure> event:

def resize(event):
    print("New size is: {}x{}".format(event.width, event.height))

root.bind("<Configure>", resize)

You can do it by calling

root.state('zoomed')