Support C++ import python on windows for paddle

Author: zhwesky2010

python/paddle/dataset/image.py

@@ -40,13 +40,14 @@
     import subprocess
     import sys
     if sys.platform == 'win32':
-        interpreter = sys.exec_prefix + "\\" + "python"
+        interpreter = sys.exec_prefix + "\\" + "python.exe"
     else:
         interpreter = sys.executable
     import_cv2_proc = subprocess.Popen(
         [interpreter, "-c", "import cv2"],
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE)
+    out, err = import_cv2_proc.communicate()
     retcode = import_cv2_proc.poll()
     if retcode != 0:
         cv2 = None

python/paddle/fluid/tests/unittests/cc_imp_py_test.cc

@@ -22,7 +22,7 @@ TEST(CC, IMPORT_PY) {
   ASSERT_TRUE(Py_IsInitialized());
 
   // 1. C/C++ Run Python simple string
-  std::cout << PyRun_SimpleString("import paddle");
+  ASSERT_FALSE(PyRun_SimpleString("import paddle"));
   ASSERT_FALSE(PyRun_SimpleString("print(paddle.to_tensor(1))"));
 
   // 2. C/C++ Run Python funciton