# running on Windows XP, Python 3.1

from tkinter import *
from tkinter.ttk import *
from tkinter import font

root = Tk()
root.geometry('+300+300')

fixed9 = font.Font(family='Courier', size=9, weight='normal')

style = Style()

# this works for Button, partially Combobox and Entry (not font)
##style.configure('.',font=fixed9,foreground='red')

# this changes top window foreground, not font, nothing in dropdown
##style.configure('TCombobox',font=fixed9,foreground='red')

# this changes foreground, not font
##style.configure('TEntry',font=fixed9,foreground='red')

# a frame
f1 = Frame(root)
f1.pack()

# a button
bt = Button(f1)
bt.pack()
bt['text'] = 'DEMO'

# an entry
en = Entry(f1)
en.pack()
en.insert(0,'DEMO')

# a combobox
cb = Combobox(f1)
cb.pack()
cb['values'] = ('DEMO','Cat','Mouse','Dog')
cb.current(0)

# this works for Combobox top window, not dropdown
##cb.configure(font=fixed9,foreground='red')

# this works for Combobox top window, not dropdown
##cb['font'] = fixed9
##cb['foreground'] = 'red'

# this works on Entry
##en['font'] = fixed9
##en['foreground'] = 'red'

root.mainloop()