import re
sample = """Name: @s
Owner: @a[tag=Admin]"""
target = r"(\s*\w+:\s*)(@[sae](?:\[[\w{}=, ]*])?)"
listOfTuples = re.findall(target, sample)
lst = [s for tpl in listOfTuples for s in tpl]
print(lst)
aW1wb3J0IHJlCgpzYW1wbGUgPSAiIiJOYW1lOiBAcwpPd25lcjogQGFbdGFnPUFkbWluXSIiIgp0YXJnZXQgPSByIihccypcdys6XHMqKShAW3NhZV0oPzpcW1tcd3t9PSwgXSpdKT8pIgoKbGlzdE9mVHVwbGVzID0gcmUuZmluZGFsbCh0YXJnZXQsIHNhbXBsZSkKbHN0ID0gW3MgZm9yIHRwbCBpbiBsaXN0T2ZUdXBsZXMgZm9yIHMgaW4gdHBsXQpwcmludChsc3Qp