use filename_to_list from filemanip

Author: oesteban

nipype/testing/fixtures.py

@@ -16,6 +16,7 @@
 from io import open
 from builtins import str
 
+from nipype.utils.filemanip import filename_to_list
 from nipype.interfaces.fsl import Info
 from nipype.interfaces.fsl.base import FSLCommand
 
@@ -30,10 +31,7 @@ def analyze_pair_image_files(outdir, filelist, shape):
 
 
 def nifti_image_files(outdir, filelist, shape):
-    if not isinstance(filelist, (list, tuple)):
-        filelist = [filelist]
-
-    for f in filelist:
+    for f in filename_to_list(filelist):
         img = np.random.random(shape)
         nb.Nifti1Image(img, np.eye(4), None).to_filename(
             os.path.join(outdir, f))