import re

pattern = r"'Field':\s+'\[([0-9]+,\s*[0-9]+)]'"

s = "{'Port': '2', 'Array': '[0, 0]', 'Field': '[2,2]', 'foo': '[0, 0]' , 'bar': '[9, 9]'}"

m = re.search(pattern, s)
if m:
    print(m.group(1))