python - 错误: value of type 'PyObject' (aka '_object' ) is not contextually convertible to 'bool'

Question

我将 python 模块作为 PyObject 传递给 C。我想使用以下形式检查该值在我的 C 代码中是否为 NONE:

int func(PyObject tmp)
{
   if(tmp)
    { 
     // etc

我收到以下错误。如何从 PyObject 转换为 bool 值，类似于 Python 的 if 函数的行为方式。值得注意的是，当 tmp 是 boost::python::object 变量时，此命令按预期工作。

ex_program.cpp:72:7: error: value of type 'PyObject' (aka '_object') is not contextually convertible to 'bool'
  if (tmp)
      ^~~

Answer 1

PyObject_IsTrue seems to do what you want :

int PyObject_IsTrue(PyObject *o)

    Returns 1 if the object o is considered to be true, and 0 otherwise. This is equivalent to the Python expression not not o. On failure, return -1.