"Traceback (most recent call last):"?

Question

Python

import urllib.request
import os
os.system('cls')

link = " https://api.nasa.gov/planetary/apod?api_key=DEMO_K... "

open_link = urllib.request.urlopen(link)

data = open_link.read()

print(data)

metadata = {
data
}

print(["url"])

This error keeps popping up, what should I do? And if someone knows how to get the URL to the image, that would be nice too, thanks!