Python3: How to dynamically resize button text in tkinter/ttk?

The example below shows two techniques, one activated by re-sizing the window (see the resize() method, bound to the <Configure> event), and the other by directly changing the size of the font (see the mutate() method).

Other code necessary to get resizing working is the grid configuration code in the __init__() method.

When running the example, there is some interaction between the two methods, but I think in a 'real' situation one technique would be sufficient, so that issue won't arise.

from tkinter import *from tkinter.ttk import *class ButtonApp(Frame):    """Container for the buttons."""    def __init__(self, master=None):        """Initialize the frame and its children."""        super().__init__(master)        self.createWidgets()        # configure the frame's resize behaviour        master.columnconfigure(0, weight=1)        master.rowconfigure(0, weight=1)        self.grid(sticky=(N,S,E,W))        # configure resize behaviour for the frame's children        self.columnconfigure(0, weight=1)        self.rowconfigure(0, weight=1)        self.rowconfigure(0, weight=1)        # bind to window resize events        self.bind('<Configure>', self.resize)    def createWidgets(self):        """Make the widgets."""        # this button mutates        self.mutantButton = Button(self, text='Press Me',                                   style='10.TButton')        self.mutantButton.grid(column=0, row=0, sticky=(N,S,E,W))        self.mutantButton['command'] = self.mutate        # an ordinary quit button for comparison        self.quitButton = Button(self, text='Quit', style='TButton')        self.quitButton.grid(column=0, row=1, sticky=(N,S,E,W))        self.quitButton['command'] = self.quit    def mutate(self):        """Rotate through the styles by hitting the button."""        style = int(self.mutantButton['style'].split('.')[0])        newStyle = style + 5        if newStyle > 50: newStyle = 10        print('Choosing font '+str(newStyle))        self.mutantButton['style'] = fontStyle[newStyle]        # resize the frame        # get the current geometries        currentGeometry = self._root().geometry()        w, h, x, y = self.parseGeometry(currentGeometry)        reqWidth = self.mutantButton.winfo_reqwidth()        reqHeight = self.mutantButton.winfo_reqheight()        # note assume height of quit button is constant at 20.        w = max([w, reqWidth])        h = 20 + reqHeight        self._root().geometry('%dx%d+%d+%d' % (w, h, x, y))    def parseGeometry(self, geometry):        """Geometry parser.        Returns the geometry as a (w, h, x, y) tuple."""        # get w        xsplit = geometry.split('x')        w = int(xsplit[0])        rest = xsplit[1]        # get h, x, y        plussplit = rest.split('+')        h = int(plussplit[0])        x = int(plussplit[1])        y = int(plussplit[2])        return w, h, x, y    def resize(self, event):        """Method bound to the <Configure> event for resizing."""        # get geometry info from the root window.        wm, hm = self._root().winfo_width(), self._root().winfo_height()        # choose a font height to match        # note subtract 30 for the button we are NOT scaling.        # note we assume optimal font height is 1/2 widget height.        fontHeight = (hm - 20) // 2        print('Resizing to font '+str(fontHeight))        # calculate the best font to use (use int rounding)        bestStyle = fontStyle[10] # use min size as the fallback        if fontHeight < 10: pass # the min size        elif fontHeight >= 50: # the max size            bestStyle = fontStyle[50]        else: # everything in between            bestFitFont = (fontHeight // 5) * 5            bestStyle = fontStyle[bestFitFont]        # set the style on the button        self.mutantButton['style'] = bestStyleroot = Tk()root.title('Alice in Pythonland')# make a dictionary of sized font styles in the range of interest.fontStyle = {}for font in range(10, 51, 5):    styleName = str(font)+'.TButton'    fontName = ' '.join(['helvetica', str(font), 'bold'])    fontStyle[font] = styleName    Style().configure(styleName, font=fontName)# run the appapp = ButtonApp(master=root)app.mainloop()root.destroy()