Merge pull request #16523 from mantidproject/MultipleFileProperty_in_python

Expose MultipleFileProperty constructor to python

Framework/PythonInterface/mantid/api/src/Exports/MultipleFileProperty.cpp

 #include "MantidAPI/MultipleFileProperty.h"
+#include "MantidPythonInterface/kernel/Converters/PySequenceToVector.h"
+#include "MantidPythonInterface/kernel/IsNone.h"
 #include "MantidPythonInterface/kernel/PropertyWithValueExporter.h"
 #include <boost/python/class.hpp>
 #include <boost/python/list.hpp>
+#include <boost/python/make_constructor.hpp>
 #include <boost/python/str.hpp>
 
 using Mantid::API::MultipleFileProperty;
 using Mantid::Kernel::PropertyWithValue;
+using Mantid::PythonInterface::Converters::PySequenceToVector;
 using Mantid::PythonInterface::PropertyWithValueExporter;
 using namespace boost::python;
 
@@ -22,29 +26,37 @@ typedef std::vector<std::vector<std::string>> HeldType;
  */
 boost::python::object valueAsPyObject(MultipleFileProperty &self) {
   const HeldType &propValue = self();
-  boost::python::object result;
-  if (propValue.size() == 1 &&
-      propValue[0].size() == 1) // Special case, unwrap the vector
-  {
-    result = boost::python::str(propValue[0][0]);
-  } else {
-    // Build a list of lists to mimic the behaviour of MultipleFileProperty
-    boost::python::list fileList;
-    for (const auto &filenames : propValue) {
-      if (filenames.size() == 1) {
-        fileList.append(filenames.front());
-      } else {
-        boost::python::list groupList;
-        for (const auto &filename : filenames) {
-          groupList.append(filename);
-        }
-        fileList.append(groupList);
+
+  // Build a list of lists to mimic the behaviour of MultipleFileProperty
+  boost::python::list fileList;
+  for (const auto &filenames : propValue) {
+    if (filenames.size() == 1) {
+      fileList.append(filenames.front());
+    } else {
+      boost::python::list groupList;
+      for (const auto &filename : filenames) {
+        groupList.append(filename);
       }
+      fileList.append(groupList);
     }
-    result = fileList;
   }
 
-  return result;
+  return fileList;
+}
+
+MultipleFileProperty *
+createMultipleFileProperty(const std::string &name,
+                           const object &extensions = object()) {
+  std::vector<std::string> extsAsVector;
+  if (!Mantid::PythonInterface::isNone(extensions)) {
+    extract<std::string> extractor(extensions);
+    if (extractor.check()) {
+      extsAsVector = std::vector<std::string>(1, extractor());
+    } else {
+      extsAsVector = PySequenceToVector<std::string>(extensions)();
+    }
+  }
+  return new MultipleFileProperty(name, extsAsVector);
 }
 }
 
@@ -55,6 +67,9 @@ void export_MultipleFileProperty() {
 
   class_<MultipleFileProperty, bases<BaseClass>, boost::noncopyable>(
       "MultipleFileProperty", no_init)
+      .def("__init__", make_constructor(
+                           &createMultipleFileProperty, default_call_policies(),
+                           (arg("name"), arg("extensions") = object())))
       // Override the base class one to do something more appropriate
       .add_property("value", &valueAsPyObject);
 }

Framework/PythonInterface/test/python/mantid/api/MultipleFilePropertyTest.py

@@ -12,7 +12,10 @@ class MultipleFilePropertyTest(unittest.TestCase):
         algorithm = create_algorithm('Load', Filename='LOQ48127.raw',OutputWorkspace='w',
                                   SpectrumMin=1,SpectrumMax=1,child=True)
         prop = algorithm.getProperty("Filename")
-        self.assertTrue(isinstance(prop.value, str))
+        filenames = prop.value
+        self.assertTrue(isinstance(filenames, list))
+        self.assertTrue(isinstance(filenames[0], str))
+        self.assertEquals(len(filenames), 1)
 
     def test_value_member_returns_python_list_for_multiple_files(self):
         algorithm = create_algorithm('Load', Filename='MUSR15189,15190,15191.nxs',OutputWorkspace='w',

scripts/Interface/reduction_gui/reduction/inelastic/dgs_reduction_script.py

@@ -180,9 +180,4 @@ class DgsReductionScripter(BaseReductionScripter):
         alg = mantid.api.AlgorithmManager.createUnmanaged("Load")
         alg.initialize()
         alg.setPropertyValue('Filename',str(filename))
-        fnames=alg.getProperty('Filename').value
-        if not isinstance(fnames,list):
-            fnames=[fnames] #make a list with one element
-        return fnames
-
-
+        return alg.getProperty('Filename').value