@author jackzhenguo @desc @date 2019/2/15
16 执行字符串表示的代码
将字符串编译成python能识别或可执行的代码，也可以将文字读成字符串再编译。
In [1]: s = "print('helloworld')" In [2]: r = compile(s,"<string>", "exec") In [3]: r Out[3]: <code object <module> at 0x0000000005DE75D0, file "<string>", line 1> In [4]: exec(r) helloworld