Merge pull request #2147 from lukassnoek/master

FIX: allow grabbing a single file (fix bug assuming string is not ite…

Author: satra

nipype/interfaces/io.py

@@ -948,12 +948,11 @@ def _list_outputs(self):
         # We must convert to the local location specified
         # and download the files.
         for key,val in outputs.items():
-            #This will basically be either list-like or string-like:
-            #if it has the __iter__ attribute, it's list-like (list,
-            #tuple, numpy array) and we iterate through each of its
-            #values. If it doesn't, it's string-like (string,
-            #unicode), and we convert that value directly.
-            if hasattr(val,'__iter__'):
+            # This will basically be either list-like or string-like:
+            # if it's an instance of a list, we'll iterate through it.
+            # If it isn't, it's string-like (string, unicode), we
+            # convert that value directly.
+            if isinstance(val, (list, tuple, set)):
                 for i,path in enumerate(val):
                     outputs[key][i] = self.s3tolocal(path, bkt)
             else: