最有效的调试工具仍然是仔细的思考，再加上明智地放置的打印语句。
The most effective debugging tool is still careful thought, coupled with judiciously placed print statements.
"Every story is two stories - the one on the surface and the one hidden beneath."
世界上已经有太多谎言,不幸的是,它们一半都是真的。