Bug fixes in the python interface

Fixed handling species with same name as predefined species.
Removed dependency on six

2 files changed, 10 insertions, 5 deletions

diff --git a/Python/pywarpx/Bucket.py b/Python/pywarpx/Bucket.py
index cd5c81793..c73b3dac9 100644
--- a/Python/pywarpx/Bucket.py
+++ b/Python/pywarpx/Bucket.py
@@ -1,5 +1,3 @@
-from six import iteritems
-
 class Bucket(object):
     """
     The purpose of this class is to be a named bucket for holding attributes.
@@ -25,7 +23,7 @@ class Bucket(object):
     def attrlist(self):
         "Concatenate the attributes into a string"
         result = []
-        for attr, value in iteritems(self.argvattrs):
+        for attr, value in self.argvattrs.items():
             if value is None:
                 continue
             # --- repr is applied to value so that for floats, all of the digits are included.
diff --git a/Python/pywarpx/WarpX.py b/Python/pywarpx/WarpX.py
index d7a37a6fa..f1fb9918a 100644
--- a/Python/pywarpx/WarpX.py
+++ b/Python/pywarpx/WarpX.py
@@ -30,10 +30,17 @@ class WarpX(Bucket):
         argv += laser.attrlist()
 
         # --- Search through species_names and add any predefined particle objects in the list.
-        # --- assuming that only the built in particle types are being used.
+        particles_list_names = [p.instancename for p in particles_list]
         for pstring in particles.species_names.split(' '):
-            if hasattr(Particles, pstring):
+            if pstring in particles_list_names:
+                # --- The species is already included in particles_list
+                continue
+            elif hasattr(Particles, pstring):
+                # --- Add the predefined species to particles_list
                 particles_list.append(getattr(Particles, pstring))
+                particles_list_names.append(pstring)
+            else:
+                raise Exception('Species %s listed in species_names not defined'%pstring)
 
         for particle in particles_list:
             argv += particle.attrlist()