总结一下 Pytest 和 Python Unitest 相关的基础用法和学习心得。

因为 GIL（全局解释器锁）, python 只有一个 GIL, 运行时只有拿到这个锁才能执行，同一时间只有一个获得 GIL 的线程在跑，其他线程都在等待状态。

相当于每个 CPU 在同一时间只能执行一个线程。

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