import re
regex = r"\b[A-Za-z]{3,} [a-zA-Z\d]{1,2},? [a-zA-Z\d]{4}\b|\([a-zA-Z\d]+\)[a-zA-Z\d]{3}-[a-zA-Z\d]{4}\b"
test_str = ("Jan 6, xxxx or (xxx)xxx-1234\n"
"Jan 16, xxxx or (xxx)xxx-1234\n"
"January 9 xxxx\n"
"(xxx)xxx-1234")
matches = re.sub(regex, lambda x: x.group().replace('x', '1'), test_str)
print(matches)
aW1wb3J0IHJlCgpyZWdleCA9IHIiXGJbQS1aYS16XXszLH0gW2EtekEtWlxkXXsxLDJ9LD8gW2EtekEtWlxkXXs0fVxifFwoW2EtekEtWlxkXStcKVthLXpBLVpcZF17M30tW2EtekEtWlxkXXs0fVxiIgp0ZXN0X3N0ciA9ICgiSmFuIDYsIHh4eHggb3IgKHh4eCl4eHgtMTIzNFxuIgoJIkphbiAxNiwgeHh4eCBvciAoeHh4KXh4eC0xMjM0XG4iCgkiSmFudWFyeSA5IHh4eHhcbiIKCSIoeHh4KXh4eC0xMjM0IikKbWF0Y2hlcyA9IHJlLnN1YihyZWdleCwgbGFtYmRhIHg6IHguZ3JvdXAoKS5yZXBsYWNlKCd4JywgJzEnKSwgIHRlc3Rfc3RyKQpwcmludChtYXRjaGVzKQ==