For coding and maintenance, compared to SPL, Python is THE nightmare（~-~）. Python provides so many types of set data, each has its own adaptation scenarios and operation rules, which is dizzying. And the transitions between them are particularly smooth, and if you're not careful, you'll calculate out something you don’t recognize. A a result, programming basically relies on googling, and you don't know why even you are right, and you’ll have to google again next time. SPL has just one type of set data, which can fit in any case.