1 #include "PredictorWrapper.h"
7 namespace py = boost::python;
10 using namespace suanzi;
13 PredictorWrapperWPtr PredictorWrapper::instance;
15 const static std::string PREDICTOR_PY_DIR = "./python";
16 const static std::string TAG = "PredictorWrapper";
18 static std::string parse_python_exception();
21 boost::python::list toPythonList(const std::vector<T>& v) {
22 typename std::vector<T>::iterator iter;
23 boost::python::list list;
24 for(const auto& vv : v){
30 PredictorWrapperPtr PredictorWrapper::create(const std::string& fname)
33 return PredictorWrapperPtr();
35 PredictorWrapperPtr ins (new PredictorWrapper(fname));
40 void PredictorWrapper::dump()
42 LOG_DEBUG(TAG, "dump");
45 py::object ret = this->dump_func();
46 ss = py::extract<std::string>(ret);
47 } catch (boost::python::error_already_set const &){
48 std::string perror_str = parse_python_exception();
49 LOG_ERROR(TAG, "Error in Python: " + perror_str)
54 double PredictorWrapper::predict(int index, const std::vector<double>& ff)
56 LOG_DEBUG(TAG, "predict");
59 ret = this->predict_func(index, toPythonList(ff));
60 } catch (boost::python::error_already_set const &){
61 std::string perror_str = parse_python_exception();
62 LOG_ERROR(TAG, "Error in Python: " + perror_str)
64 double rr = py::extract<double>(ret);
65 LOG_DEBUG(TAG, "return: " + std::to_string(rr));
69 PredictorWrapper::PredictorWrapper(const std::string& fname)
73 py::object main_module = py::import("__main__");
74 py::object main_namespace = main_module.attr("__dict__");
75 py::exec("import sys", main_namespace);
76 std::string cmd = "sys.path.insert(0, '" + PREDICTOR_PY_DIR + "')";
77 py::exec(cmd.c_str(), main_namespace);
78 py::exec("import signal", main_namespace);
79 py::exec("signal.signal(signal.SIGINT, signal.SIG_DFL)", main_namespace);
80 py::object predictor_mod = py::import("predictor");
81 py::object predictor_init = predictor_mod.attr("init");
82 dump_func = predictor_mod.attr("dump");
83 predict_func = predictor_mod.attr("predict");
84 predictor_init(fname.c_str());
85 } catch (boost::python::error_already_set const &){
86 std::string perror_str = parse_python_exception();
87 LOG_ERROR(TAG, "Error in Python: " + perror_str)
91 static std::string parse_python_exception(){
92 PyObject *type_ptr = NULL, *value_ptr = NULL, *traceback_ptr = NULL;
93 // Fetch the exception info from the Python C API
94 PyErr_Fetch(&type_ptr, &value_ptr, &traceback_ptr);
97 std::string ret("Unfetchable Python error");
98 // If the fetch got a type pointer, parse the type into the exception string
100 py::handle<> h_type(type_ptr);
101 py::str type_pstr(h_type);
102 // Extract the string from the boost::python object
103 py::extract<std::string> e_type_pstr(type_pstr);
104 // If a valid string extraction is available, use it
105 // otherwise use fallback
106 if(e_type_pstr.check())
109 ret = "Unknown exception type";
111 // Do the same for the exception value (the stringification of the exception)
112 if(value_ptr != NULL){
113 py::handle<> h_val(value_ptr);
115 py::extract<std::string> returned(a);
117 ret += ": " + returned();
119 ret += std::string(": Unparseable Python error: ");
121 // Parse lines from the traceback using the Python traceback module
122 if(traceback_ptr != NULL){
123 py::handle<> h_tb(traceback_ptr);
124 // Load the traceback module and the format_tb function
125 py::object tb(py::import("traceback"));
126 py::object fmt_tb(tb.attr("format_tb"));
127 // Call format_tb to get a list of traceback strings
128 py::object tb_list(fmt_tb(h_tb));
129 // Join the traceback strings into a single string
130 py::object tb_str(py::str("\n").join(tb_list));
131 // Extract the string, check the extraction, and fallback in necessary
132 py::extract<std::string> returned(tb_str);
134 ret += ": " + returned();
136 ret += std::string(": Unparseable Python traceback");