import tkinter as tk

root = tk.Tk()
root.title("Rada čtverců")

canvas = tk.Canvas(root, width=400, height=100)
canvas.pack()

x = 10

for _ in range(9):
    canvas.create_rectangle(x, 10, x + 30, 40, outline="black", fill="red")
    x += 40

# mainloop hihi
root.mainloop()