python - 后期变量绑定的后期代码评估？

Question

您可以推迟代码执行：

In [12]: v = 5

In [13]: e = ' v * 2 '

In [14]: eval(e)
Out[14]: 10

我想对普通 python 代码进行后期评估而不将其分配给字符串？

有没有一种技术可以做到这一点？关闭？ __call__?

另一个例子：

In [15]: b = bitarray('10110')

In [16]: p = Pipe(lambda x : x * 2 )

In [17]: e = ' b | p '

In [18]: eval(e)
Out[18]: bitarray('1011010110')

我正在尝试构建类似于 TensorFlow 和 keras 的执行流程的图表/管道，然后传递数据并收集结果......它比这更复杂，因为流程不是直截了当的......

score 2 · Accepted Answer

The usual way to do this is with a function.

def e():
    return v * 2

>>> v = 5
>>> e()
10
>>> v = 6
>>> e()
12

I must also say that I'm not in favor of functions that don't take their input as explicit parameters. Grabbing a global is cheating.

1 回答 1