how to change font in tkinter

import tkinter.font as font

#create Font object
myFont = font.Font(family='Helvetica')

button = Button(parent, font=myFont)
button = Button(parent)
button['font'] = myFont

Here is what the above code is Doing:
1. Create a Font object.
2. Create a Button widget.
3. Set the Button widget’s font to the Font object.
4. Or, set the Button widget’s font after the widget has been created.