change all font size at once tkinter code example
Example: how to change the font of a label in tkinter
#How to change the font of a label in Tkinter
#Import
from tkinter import *
#Screen
window = Tk()
window.title("New Window")
window.geometry("300x250")
Label(window, text = "This is my new project in python!", font = ("Bahnschrift", 14)).pack()
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#'font' tells python that we are going to do something with the font
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#'()' are needed becuase that is just how python works
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#'"___"' put your font name in the quotes
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#10 put vyour fontsize after adding a comma after the font name
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