fix: datagrabber output order for files

Author: satra

nipype/interfaces/io.py

@@ -538,11 +538,11 @@ def _list_outputs(self):
                             raise IOError(msg)
                         else:
                             warn(msg)
-                        outputs[key].insert(i, None)
+                        outputs[key].append(None)
                     else:
                         if self.inputs.sort_filelist:
                             outfiles.sort()
-                        outputs[key].insert(i, list_to_filename(outfiles))
+                        outputs[key].append(list_to_filename(outfiles))
             if any([val is None for val in outputs[key]]):
                 outputs[key] = []
             if len(outputs[key]) == 0:

nipype/interfaces/tests/test_io.py

@@ -15,6 +15,26 @@ def test_datagrabber():
     yield assert_equal, dg.inputs.base_directory, Undefined
     yield assert_equal, dg.inputs.template_args,{'outfiles': []}
 
+def test_datagrabber_order():
+    tempdir = mkdtemp()
+    file1 = mkstemp(prefix='sub002_L1_R1.q', dir=tempdir)
+    file2 = mkstemp(prefix='sub002_L1_R2.q', dir=tempdir)
+    file3 = mkstemp(prefix='sub002_L2_R1.q', dir=tempdir)
+    file4 = mkstemp(prefix='sub002_L2_R2.q', dir=tempdir)
+    dg = nio.DataGrabber(infields=['sid'])
+    dg.inputs.base_directory = tempdir
+    dg.inputs.template = '%s_L%d_R?.q*'
+    dg.inputs.template_args = {'outfiles': [['sid', 1], ['sid', 2]]}
+    dg.inputs.sid = 'sub002'
+    dg.inputs.sort_filelist = True
+    res = dg.run()
+    outfiles = res.outputs.outfiles
+    yield assert_true, 'sub002_L1_R1' in outfiles[0][0]
+    yield assert_true, 'sub002_L1_R2' in outfiles[0][1]
+    yield assert_true, 'sub002_L2_R1' in outfiles[1][0]
+    yield assert_true, 'sub002_L2_R2' in outfiles[1][1]
+    shutil.rmtree(tempdir)
+
 def test_datasink():
     ds = nio.DataSink()
     yield assert_true, ds.inputs.parameterization