import re
p = re.compile(r'\(([^);]+)')
test_str = "1. yada yada yada (This is a string; \"This is a thing\")\n2. blah blah blah (This is also a string)"
print(p.findall(test_str))
aW1wb3J0IHJlCnAgPSByZS5jb21waWxlKHInXCgoW14pO10rKScpCnRlc3Rfc3RyID0gIjEuIHlhZGEgeWFkYSB5YWRhIChUaGlzIGlzIGEgc3RyaW5nOyBcIlRoaXMgaXMgYSB0aGluZ1wiKVxuMi4gYmxhaCBibGFoIGJsYWggKFRoaXMgaXMgYWxzbyBhIHN0cmluZykiCnByaW50KHAuZmluZGFsbCh0ZXN0X3N0cikp