import re

filez = """url(https://www.google.com)
url('Inter-Black.ttf')
url(Inter-Black.ttf)
url('Inter-Black.ttf)
url('/fonts/user/Inter-Black.ttf')
url('/fonts/user/mywebsite/Inter-Black.ttf')
"""

p = r"(url\()(?!https?://www\.google\.com)(')?/?([^()']*)((?(2)')\))"
filez = re.sub(p, r"\1\2/static/user/\3\4", filez)
print(filez)