为什么python在解释之前将源码编译为字节码？

几乎没有解释器真的直接解释代码，一行一行 - 它太低效了。几乎所有的解释器使用一些可以容易执行的中间表示。此外，可以对此中间代码执行小的优化。

Nearly no interpreter really interprets code directly, line by line – it's simply too inefficient. Almost all interpreters use some intermediate representation which can be executed easily. Also, small optimizations can be performed on this intermediate code.

Python还存储此代码，这对下次执行此代码有巨大的优势：Python不必须解析代码;解析是编译过程中最慢的部分。因此，字节码表示大大减少了执行开销。

Python furthermore stores this code which has a huge advantage for the next time this code gets executed: Python doesn't have to parse the code anymore; parsing is the slowest part in the compile process. Thus, a bytecode representation reduces execution overhead quite substantially.