import re
s = "I have a string submarine I want to be able to detect marines as a match"
kw = "submarine"
r = re.compile(r"\b[{0}]+\b".format(kw))
print(r.findall(s))
aW1wb3J0IHJlCnMgPSAiSSBoYXZlIGEgc3RyaW5nIHN1Ym1hcmluZSBJIHdhbnQgdG8gYmUgYWJsZSB0byBkZXRlY3QgbWFyaW5lcyBhcyBhIG1hdGNoIgprdyA9ICJzdWJtYXJpbmUiCnIgID0gcmUuY29tcGlsZShyIlxiW3swfV0rXGIiLmZvcm1hdChrdykpCnByaW50KHIuZmluZGFsbChzKSk=