In this video I’ll show you how to switch between light and dark mode programatically with CustomTkinter and Python.

Most people pick a mode, dark or light, when coding their project. But you can switch in real time from your app too!

I’ll show you how to do it in this video…

Python Code: ctk_lightdark.py
(Github Code)

from tkinter import *
import customtkinter

customtkinter.set_appearance_mode("dark")  # Modes: system (default), light, dark
customtkinter.set_default_color_theme("dark-blue")  # Themes: blue (default), dark-blue, green

#root = Tk()
root = customtkinter.CTk()

root.title('Tkinter.com - CustomTkinter Light Dark Modes')
root.iconbitmap('images/codemy.ico')
root.geometry('700x450')

mode = "dark"

def change_colors(choice):
	customtkinter.set_default_color_theme(choice)

def change():
	global mode
	if mode == "dark":
		customtkinter.set_appearance_mode("light")
		mode = "light"
		# Clear text box
		my_text.delete(0.0, END)
		my_text.insert(END, "This is Light Mode...")
	else:
		customtkinter.set_appearance_mode("dark")
		mode = "dark"
		# Clear text box
		my_text.delete(0.0, END)
		my_text.insert(END, "This is Dark Mode...")


my_text = customtkinter.CTkTextbox(root, width=600, height=300)
my_text.pack(pady=20)

my_button = customtkinter.CTkButton(root, text="Change Light/Dark", command=change)
my_button.pack(pady=20)

colors = ["blue", "dark-blue", "green"]
my_option = customtkinter.CTkOptionMenu(root, values=colors, command=change_colors)
my_option.pack(pady=10)







root.mainloop()


John Elder

John is the CEO of Codemy.com where he teaches over 100,000 students how to code! He founded one of the Internet's earliest advertising networks and sold it to a publicly company at the height of the first dot com boom. After that he developed the award-winning Submission-Spider search engine submission software that's been used by over 3 million individuals, businesses, and governments in over 42 countries. He's written several Amazon #1 best selling books on coding, and runs a popular Youtube coding channel.

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John Elder

John is the CEO of Codemy.com where he teaches over 100,000 students how to code! He founded one of the Internet's earliest advertising networks and sold it to a publicly company at the height of...