Pillow

[juuls04]

from tkinter import *
from PIL import Image,ImageTk

root = Tk()

img = ImageTk.PhotoImage(Image.open('red-circle.png'))
label = Label(image=my_img)
label.pack

root.mainloop()

When I run this, I get this error: FileNotFoundError: [Errno 2] No such file or directory: 'red-circle.png'.

I want to upload an image into my program and I saw that Pillow (PIL) was a good option. I've been trying for half an hour now but i just dont know how i can upload/import an image into my program. Does somebody know what is the best way to do this?
Thanks in advance!