diff --git a/python/examples/pizza/dump.py b/python/examples/pizza/dump.py
index 632e534e8f..ec18cba62e 100644
--- a/python/examples/pizza/dump.py
+++ b/python/examples/pizza/dump.py
@@ -6,6 +6,10 @@
 # certain rights in this software.  This software is distributed under 
 # the GNU General Public License.
 
+# for python3 compatibility
+
+from __future__ import print_function
+
 # dump tool
 
 oneline = "Read, write, manipulate dump files and particle attributes"
@@ -179,9 +183,7 @@ d.extra(data)				   extract bond/tri/line list from data
 
 # Imports and external programs
 
-from __future__ import print_function
-
-import sys, commands, re, glob, types
+import sys, re, glob, types
 from os import popen
 from math import *             # any function could be used by set()
 
@@ -222,7 +224,7 @@ class dump:
     self.flist = []
     for word in words: self.flist += glob.glob(word)
     if len(self.flist) == 0 and len(list) == 1:
-      raise StandardError,"no dump file specified"
+      raise StandardError("no dump file specified")
     
     if len(list) == 1:
       self.increment = 0
@@ -247,19 +249,19 @@ class dump:
       snap = self.read_snapshot(f)
       while snap:
         self.snaps.append(snap)
-        print snap.time,
+        print(snap.time,end='')
         sys.stdout.flush()
         snap = self.read_snapshot(f)
 
       f.close()
-    print
+    print()
 
     # sort entries by timestep, cull duplicates
 
     self.snaps.sort(self.compare_time)
     self.cull()
     self.nsnaps = len(self.snaps)
-    print "read %d snapshots" % self.nsnaps
+    print("read %d snapshots" % self.nsnaps)
 
     # select all timesteps and atoms
 
@@ -268,36 +270,36 @@ class dump:
     # set default names for atom columns if file wasn't self-describing
     
     if len(self.snaps) == 0:
-      print "no column assignments made"
+      print("no column assignments made")
     elif len(self.names):
-      print "assigned columns:",self.names2str()
+      print("assigned columns:",self.names2str())
     elif self.snaps[0].atoms == None:
-      print "no column assignments made"
+      print("no column assignments made")
     elif len(self.snaps[0].atoms[0]) == 5:
       self.map(1,"id",2,"type",3,"x",4,"y",5,"z")
-      print "assigned columns:",self.names2str()
+      print("assigned columns:",self.names2str())
     elif len(self.snaps[0].atoms[0]) == 8:
       self.map(1,"id",2,"type",3,"x",4,"y",5,"z",6,"ix",7,"iy",8,"iz")
-      print "assigned columns:",self.names2str()
+      print("assigned columns:",self.names2str())
     else:
-      print "no column assignments made"
+      print("no column assignments made")
 
     # if snapshots are scaled, unscale them
 
     if (not self.names.has_key("x")) or \
        (not self.names.has_key("y")) or \
        (not self.names.has_key("z")):
-      print "no unscaling could be performed"
+      print("no unscaling could be performed")
     elif self.nsnaps > 0:
       if self.scaled(self.nsnaps-1): self.unscale()
-      else: print "dump is already unscaled"
+      else: print("dump is already unscaled")
 
   # --------------------------------------------------------------------
   # read next snapshot from list of files
 
   def next(self):
 
-    if not self.increment: raise StandardError,"cannot read incrementally"
+    if not self.increment: raise StandardError("cannot read incrementally")
 
     # read next snapshot in current file using eof as pointer
     # if fail, try next file
@@ -309,15 +311,15 @@ class dump:
       snap = self.read_snapshot(f)
       if not snap:
         self.nextfile += 1
-	if self.nextfile == len(self.flist): return -1
+        if self.nextfile == len(self.flist): return -1
         f.close()
-	self.eof = 0
-	continue
+        self.eof = 0
+        continue
       self.eof = f.tell()
       f.close()
       try:
         self.findtime(snap.time)
-	continue
+        continue
       except: break
 
     # select the new snapshot with all its atoms
@@ -415,7 +417,7 @@ class dump:
   
   def map(self,*pairs):
     if len(pairs) % 2 != 0:
-      raise StandardError, "dump map() requires pairs of mappings"
+      raise StandardError("dump map() requires pairs of mappings")
     for i in range(0,len(pairs),2):
       j = i + 1
       self.names[pairs[j]] = pairs[i]-1
@@ -432,15 +434,15 @@ class dump:
         self.nsnaps -= 1
         ndel += 1
       else: i += 1
-    print "%d snapshots deleted" % ndel
-    print "%d snapshots remaining" % self.nsnaps
+    print("%d snapshots deleted" % ndel)
+    print("%d snapshots remaining" % self.nsnaps)
 
   # --------------------------------------------------------------------
   # scale coords to 0-1 for all snapshots or just one
 
   def scale(self,*list):
     if len(list) == 0:
-      print "Scaling dump ..."
+      print("Scaling dump ...")
       x = self.names["x"]
       y = self.names["y"]
       z = self.names["z"]
@@ -468,7 +470,7 @@ class dump:
 
   def unscale(self,*list):
     if len(list) == 0:
-      print "Unscaling dump ..."
+      print("Unscaling dump ...")
       x = self.names["x"]
       y = self.names["y"]
       z = self.names["z"]
@@ -495,7 +497,7 @@ class dump:
   # wrap coords from outside box to inside
 
   def wrap(self):
-    print "Wrapping dump ..."
+    print("Wrapping dump ...")
 
     x = self.names["x"]
     y = self.names["y"]
@@ -517,7 +519,7 @@ class dump:
   # unwrap coords from inside box to outside
 
   def unwrap(self):
-    print "Unwrapping dump ..."
+    print("Unwrapping dump ...")
 
     x = self.names["x"]
     y = self.names["y"]
@@ -539,7 +541,7 @@ class dump:
   # wrap coords to same image as atom ID stored in "other" column
 
   def owrap(self,other):
-    print "Wrapping to other ..."
+    print("Wrapping to other ...")
     
     id = self.names["id"]
     x = self.names["x"]
@@ -583,12 +585,12 @@ class dump:
 
   def sort(self,*list):
     if len(list) == 0:
-      print "Sorting selected snapshots ..."
+      print("Sorting selected snapshots ...")
       id = self.names["id"]
       for snap in self.snaps:
         if snap.tselect: self.sort_one(snap,id)
     elif type(list[0]) is types.StringType:
-      print "Sorting selected snapshots by %s ..." % list[0]
+      print("Sorting selected snapshots by %s ..." % list[0])
       id = self.names[list[0]]
       for snap in self.snaps:
         if snap.tselect: self.sort_one(snap,id)
@@ -616,19 +618,19 @@ class dump:
     else: f = open(file,"a")
     for snap in self.snaps:
       if not snap.tselect: continue
-      print snap.time,
+      print(snap.time,end='')
       sys.stdout.flush()
 
       if header:
-        print >>f,"ITEM: TIMESTEP"
-        print >>f,snap.time
-        print >>f,"ITEM: NUMBER OF ATOMS"
-        print >>f,snap.nselect
-        print >>f,"ITEM: BOX BOUNDS"
-        print >>f,snap.xlo,snap.xhi
-        print >>f,snap.ylo,snap.yhi
-        print >>f,snap.zlo,snap.zhi
-        print >>f,"ITEM: ATOMS",namestr
+        print("ITEM: TIMESTEP",file=f)
+        print(snap.time,file=f)
+        print("ITEM: NUMBER OF ATOMS",file=f)
+        print(snap.nselect,file=f)
+        print("ITEM: BOX BOUNDS",file=f)
+        print(snap.xlo,snap.xhi,file=f)
+        print(snap.ylo,snap.yhi,file=f)
+        print(snap.zlo,snap.zhi,file=f)
+        print("ITEM: ATOMS",namestr,file=f)
       
       atoms = snap.atoms
       nvalues = len(atoms[0])
@@ -640,9 +642,9 @@ class dump:
             line += str(int(atoms[i][j])) + " "
           else:
             line += str(atoms[i][j]) + " "
-        print >>f,line
+        print(line,file=f)
     f.close()
-    print "\n%d snapshots" % self.nselect
+    print("\n%d snapshots" % self.nselect)
 
   # --------------------------------------------------------------------
   # write one dump file per snapshot from current selection
@@ -651,20 +653,20 @@ class dump:
     if len(self.snaps): namestr = self.names2str()
     for snap in self.snaps:
       if not snap.tselect: continue
-      print snap.time,
+      print(snap.time,end='')
       sys.stdout.flush()
       
       file = root + "." + str(snap.time)
       f = open(file,"w")
-      print >>f,"ITEM: TIMESTEP"
-      print >>f,snap.time
-      print >>f,"ITEM: NUMBER OF ATOMS"
-      print >>f,snap.nselect
-      print >>f,"ITEM: BOX BOUNDS"
-      print >>f,snap.xlo,snap.xhi
-      print >>f,snap.ylo,snap.yhi
-      print >>f,snap.zlo,snap.zhi
-      print >>f,"ITEM: ATOMS",namestr
+      print("ITEM: TIMESTEP",file=f)
+      print(snap.time,file=f)
+      print("ITEM: NUMBER OF ATOMS",file=f)
+      print(snap.nselect,file=f)
+      print("ITEM: BOX BOUNDS",file=f)
+      print(snap.xlo,snap.xhi,file=f)
+      print(snap.ylo,snap.yhi,file=f)
+      print(snap.zlo,snap.zhi,file=f)
+      print("ITEM: ATOMS",namestr,file=f)
       
       atoms = snap.atoms
       nvalues = len(atoms[0])
@@ -676,9 +678,9 @@ class dump:
             line += str(int(atoms[i][j])) + " "
           else:
             line += str(atoms[i][j]) + " "
-        print >>f,line
+        print(line,file=f)
       f.close()
-    print "\n%d snapshots" % self.nselect
+    print("\n%d snapshots" % self.nselect)
 
   # --------------------------------------------------------------------
   # find min/max across all selected snapshots/atoms for a particular column
@@ -700,7 +702,7 @@ class dump:
   # set a column value via an equation for all selected snapshots
 
   def set(self,eq):
-    print "Setting ..."
+    print("Setting ...")
     pattern = "\$\w*"
     list = re.findall(pattern,eq)
 
@@ -718,13 +720,13 @@ class dump:
     for snap in self.snaps:
       if not snap.tselect: continue
       for i in range(snap.natoms):
-        if snap.aselect[i]: exec ceq
+        if snap.aselect[i]: exec(ceq)
           
   # --------------------------------------------------------------------
   # set a column value via an input vec for all selected snapshots/atoms
 
   def setv(self,colname,vec):
-    print "Setting ..."
+    print("Setting ...")
     if not self.names.has_key(colname):
       self.newcolumn(colname)
     icol = self.names[colname]
@@ -732,7 +734,7 @@ class dump:
     for snap in self.snaps:
       if not snap.tselect: continue
       if snap.nselect != len(vec):
-        raise StandardError,"vec length does not match # of selected atoms"
+        raise StandardError("vec length does not match # of selected atoms")
       atoms = snap.atoms
       m = 0
       for i in range(snap.natoms):
@@ -767,7 +769,7 @@ class dump:
     inew = self.names[new]
 
     min,max = self.minmax(old)
-    print "min/max = ",min,max
+    print("min/max = ",min,max)
 
     gap = max - min
     invdelta = n/gap
@@ -798,7 +800,7 @@ class dump:
 
   def atom(self,n,*list):
     if len(list) == 0:
-      raise StandardError, "no columns specified"
+      raise StandardError("no columns specified")
     columns = []
     values = []
     for name in list:
@@ -814,7 +816,7 @@ class dump:
       for i in range(snap.natoms):
         if atoms[i][id] == n: break
       if atoms[i][id] != n:
-        raise StandardError, "could not find atom ID in snapshot"
+        raise StandardError("could not find atom ID in snapshot")
       for j in range(ncol):
         values[j][m] = atoms[i][columns[j]]
       m += 1
@@ -829,7 +831,7 @@ class dump:
     snap = self.snaps[self.findtime(n)]
     
     if len(list) == 0:
-      raise StandardError, "no columns specified"
+      raise StandardError("no columns specified")
     columns = []
     values = []
     for name in list:
@@ -957,7 +959,7 @@ class dump:
   def findtime(self,n):
     for i in range(self.nsnaps):
       if self.snaps[i].time == n: return i
-    raise StandardError, "no step %d exists" % n
+    raise StandardError("no step %d exists" % n)
 
   # --------------------------------------------------------------------
   # return maximum box size across all selected snapshots
@@ -1006,7 +1008,7 @@ class dump:
         nbonds = int(f.readline())
         item = f.readline()
         if not re.search("BONDS",item):
-          raise StandardError, "could not read bonds from dump file"
+          raise StandardError("could not read bonds from dump file")
 
         words = f.readline().split()
         ncol = len(words)
@@ -1029,7 +1031,7 @@ class dump:
           self.bondflag = 1
           self.bondlist = bondlist
       except:
-        raise StandardError,"could not read from bond dump file"
+        raise StandardError("could not read from bond dump file")
       
     # request bonds from data object
     
@@ -1045,7 +1047,7 @@ class dump:
           self.bondflag = 1
           self.bondlist = bondlist
       except:
-        raise StandardError,"could not extract bonds from data object"
+        raise StandardError("could not extract bonds from data object")
 
     # request tris/lines from cdata object
     
@@ -1059,7 +1061,7 @@ class dump:
           self.lineflag = 1
           self.linelist = lines
       except:
-        raise StandardError,"could not extract tris/lines from cdata object"
+        raise StandardError("could not extract tris/lines from cdata object")
 
     # request tris from mdump object
     
@@ -1068,10 +1070,10 @@ class dump:
         self.triflag = 2
         self.triobj = arg
       except:
-        raise StandardError,"could not extract tris from mdump object"
+        raise StandardError("could not extract tris from mdump object")
 
     else:
-      raise StandardError,"unrecognized argument to dump.extra()"
+      raise StandardError("unrecognized argument to dump.extra()")
       
   # --------------------------------------------------------------------
 
@@ -1105,7 +1107,7 @@ class tselect:
       snap.tselect = 1
     data.nselect = len(data.snaps)
     data.aselect.all()
-    print "%d snapshots selected out of %d" % (data.nselect,data.nsnaps)
+    print("%d snapshots selected out of %d" % (data.nselect,data.nsnaps))
 
   # --------------------------------------------------------------------
 
@@ -1117,7 +1119,7 @@ class tselect:
     data.snaps[i].tselect = 1
     data.nselect = 1
     data.aselect.all()
-    print "%d snapshots selected out of %d" % (data.nselect,data.nsnaps)
+    print("%d snapshots selected out of %d" % (data.nselect,data.nsnaps))
 
   # --------------------------------------------------------------------
 
@@ -1126,7 +1128,7 @@ class tselect:
     for snap in data.snaps:
       snap.tselect = 0
     data.nselect = 0
-    print "%d snapshots selected out of %d" % (data.nselect,data.nsnaps)
+    print("%d snapshots selected out of %d" % (data.nselect,data.nsnaps))
 
   # --------------------------------------------------------------------
 
@@ -1142,7 +1144,7 @@ class tselect:
       snap.tselect = 0
       data.nselect -= 1
     data.aselect.all()
-    print "%d snapshots selected out of %d" % (data.nselect,data.nsnaps)
+    print("%d snapshots selected out of %d" % (data.nselect,data.nsnaps))
   
   # --------------------------------------------------------------------
 
@@ -1153,12 +1155,12 @@ class tselect:
     ccmd = compile(cmd,'','single')
     for i in range(data.nsnaps):
       if not snaps[i].tselect: continue
-      exec ccmd
+      exec(ccmd)
       if not flag:
         snaps[i].tselect = 0
         data.nselect -= 1
     data.aselect.all()
-    print "%d snapshots selected out of %d" % (data.nselect,data.nsnaps)
+    print("%d snapshots selected out of %d" % (data.nselect,data.nsnaps))
 
 # --------------------------------------------------------------------
 # atom selection class
@@ -1205,19 +1207,19 @@ class aselect:
         if not snap.tselect: continue
         for i in range(snap.natoms):
           if not snap.aselect[i]: continue
-          exec ccmd
+          exec(ccmd)
           if not flag:
             snap.aselect[i] = 0
             snap.nselect -= 1
       for i in range(data.nsnaps):
         if data.snaps[i].tselect:
-          print "%d atoms of %d selected in first step %d" % \
-                (data.snaps[i].nselect,data.snaps[i].natoms,data.snaps[i].time)
+          print("%d atoms of %d selected in first step %d" % \
+                (data.snaps[i].nselect,data.snaps[i].natoms,data.snaps[i].time))
           break
       for i in range(data.nsnaps-1,-1,-1):
         if data.snaps[i].tselect:
-          print "%d atoms of %d selected in last step %d" % \
-                (data.snaps[i].nselect,data.snaps[i].natoms,data.snaps[i].time)
+          print("%d atoms of %d selected in last step %d" % \
+                (data.snaps[i].nselect,data.snaps[i].natoms,data.snaps[i].time))
           break
 
     else:                                        # one timestep
@@ -1225,7 +1227,7 @@ class aselect:
       snap = data.snaps[n]
       for i in range(snap.natoms):
         if not snap.aselect[i]: continue
-        exec ccmd
+        exec(ccmd)
         if not flag:
           snap.aselect[i] = 0
           snap.nselect -= 1
diff --git a/python/examples/pizza/gl.py b/python/examples/pizza/gl.py
index 71db5b63e7..765653c983 100644
--- a/python/examples/pizza/gl.py
+++ b/python/examples/pizza/gl.py
@@ -6,6 +6,9 @@
 # certain rights in this software.  This software is distributed under 
 # the GNU General Public License.
 
+# for python3 compatibility
+from __future__ import print_function
+
 # gl tool
 
 oneline = "3d interactive visualization via OpenGL"
@@ -73,7 +76,7 @@ g.ldef()  			   default = 0 fill
   if atom/bond/tri/line has type > # defined properties, is an error
   
 from vizinfo import colors         access color list
-print colors                       list defined color names and RGB values
+print(colors)                      list defined color names and RGB values
 colors["nickname"] = [R,G,B]       set new RGB values from 0 to 255
 
   140 pre-defined colors: red, green, blue, purple, yellow, black, white, etc
@@ -499,7 +502,7 @@ class gl:
   # add GL-specific info to each bond
   
   def reload(self):
-    print "Loading data into gl tool ..."
+    print("Loading data into gl tool ...")
     data = self.data
 
     self.timeframes = []
@@ -527,9 +530,9 @@ class gl:
       self.triframes.append(tris)
       self.lineframes.append(lines)
       
-      print time,
+      print(time,end='')
       sys.stdout.flush()
-    print
+    print()
 
     self.nframes = len(self.timeframes)
     self.distance = compute_distance(self.boxframes[0])
@@ -651,7 +654,7 @@ class gl:
         self.w.tkRedraw()
         self.save(file)
         
-        print time,
+        print(time,end='')
         sys.stdout.flush()
         i += 1
         n += 1
@@ -690,7 +693,7 @@ class gl:
                           fraction*(self.scale_stop - self.scale_start)
           self.viewupright()
 
-	if n == nstart or self.panflag: self.center = compute_center(box)
+        if n == nstart or self.panflag: self.center = compute_center(box)
 
         if bonds: self.bonds_augment(bonds)
 
@@ -706,11 +709,11 @@ class gl:
         self.w.tkRedraw()
         self.save(file)
 
-        print n,
+        print(n,end='')
         sys.stdout.flush()
         n += 1
 
-    print "\n%d images" % ncount
+    print("\n%d images" % ncount)
 
   # --------------------------------------------------------------------
 
@@ -776,11 +779,11 @@ class gl:
       ncolor = self.vizinfo.nlcolor
       for line in self.linedraw:
         itype = int(line[1])
-        if itype > ncolor: raise StandardError,"line type too big"
+        if itype > ncolor: raise StandardError("line type too big")
         red,green,blue = self.vizinfo.lcolor[itype]
         glColor3f(red,green,blue)
         thick = self.vizinfo.lrad[itype]
-	glLineWidth(thick)
+        glLineWidth(thick)
         glBegin(GL_LINES)
         glVertex3f(line[2],line[3],line[4])
         glVertex3f(line[5],line[6],line[7])
@@ -825,7 +828,7 @@ class gl:
           for bond in self.bonddraw:
             if bond[10] > bound: continue
             itype = int(bond[1])
-            if itype > ncolor: raise StandardError,"bond type too big"
+            if itype > ncolor: raise StandardError("bond type too big")
             red,green,blue = self.vizinfo.bcolor[itype]
             rad = self.vizinfo.brad[itype]
             glPushMatrix()
@@ -848,7 +851,7 @@ class gl:
             ncolor = self.vizinfo.ntcolor
             for tri in self.tridraw:
               itype = int(tri[1])
-              if itype > ncolor: raise StandardError,"tri type too big"
+              if itype > ncolor: raise StandardError("tri type too big")
               red,green,blue = self.vizinfo.tcolor[itype]
               glMaterialfv(GL_FRONT_AND_BACK,GL_EMISSION,[red,green,blue,1.0]);
               glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,self.shiny);
@@ -906,7 +909,7 @@ class gl:
                    ymin >= ylo and ymax <= yhi and zmin >= zlo and zmax <= zhi:
               if bond[10] > bound: continue
               itype = int(bond[1])
-              if itype > ncolor: raise StandardError,"bond type too big"
+              if itype > ncolor: raise StandardError("bond type too big")
               red,green,blue = self.vizinfo.bcolor[itype]
               rad = self.vizinfo.brad[itype]
               glPushMatrix()
@@ -938,7 +941,7 @@ class gl:
                      ymin >= ylo and ymax <= yhi and \
                      zmin >= zlo and zmax <= zhi:
                 itype = int(tri[1])
-                if itype > ncolor: raise StandardError,"tri type too big"
+                if itype > ncolor: raise StandardError("tri type too big")
                 red,green,blue = self.vizinfo.tcolor[itype]
                 glMaterialfv(GL_FRONT_AND_BACK,GL_EMISSION,
                              [red,green,blue,1.0]);
diff --git a/python/examples/pizza/gnu.py b/python/examples/pizza/gnu.py
index 1c6dbee033..7d796d5586 100644
--- a/python/examples/pizza/gnu.py
+++ b/python/examples/pizza/gnu.py
@@ -6,6 +6,9 @@
 # certain rights in this software.  This software is distributed under 
 # the GNU General Public License.
 
+# for python3 compatibility
+from __future__ import print_function
+
 # gnu tool
 
 oneline = "Create plots via GnuPlot plotting program"
@@ -172,8 +175,8 @@ class gnu:
     nvec = len(vectors)
     for i in range(n):
       for j in range(nvec):
-        print >>f,vectors[j][i],
-      print >>f
+        print(str(vectors[j][i])+" ",file=f,end='')
+      print ("",file=f)
     f.close()
 
   # --------------------------------------------------------------------
@@ -350,7 +353,7 @@ class gnu:
 
     self.__call__("set key off")
     cmd = 'plot '
-    for i in range(fig.ncurves):
+    for i in range(int(fig.ncurves)):
       file = self.file + ".%d.%d" % (self.current,i+1)
       if len(fig.colors) > i and fig.colors[i]:
         cmd += "'" + file + "' using 1:2 with line %d, " % fig.colors[i]
diff --git a/python/examples/pizza/pdbfile.py b/python/examples/pizza/pdbfile.py
index 1713ada043..2ca85b64da 100644
--- a/python/examples/pizza/pdbfile.py
+++ b/python/examples/pizza/pdbfile.py
@@ -6,6 +6,9 @@
 # certain rights in this software.  This software is distributed under 
 # the GNU General Public License.
 
+# for python3 compatibility
+from __future__ import print_function
+
 # pdb tool
 
 oneline = "Read, write PDB files in combo with LAMMPS snapshots"
@@ -83,7 +86,7 @@ class pdbfile:
     elif len(args) == 2:
       filestr = args[0]
       self.data = args[1]
-    else: raise StandardError, "invalid args for pdb()"
+    else: raise StandardError("invalid args for pdb()")
 
     # flist = full list of all PDB input file names
     # append .pdb if needed
@@ -97,14 +100,14 @@ class pdbfile:
       for i in xrange(len(flist)):
         if flist[i][-4:] != ".pdb": flist[i] += ".pdb"
       if len(flist) == 0:
-        raise StandardError,"no PDB file specified"
+        raise StandardError("no PDB file specified")
       self.files = flist
     else: self.files = []
 
     if len(self.files) > 1 and self.data:
-      raise StandardError, "cannot use multiple PDB files with data object"
+      raise StandardError("cannot use multiple PDB files with data object")
     if len(self.files) == 0 and not self.data:
-      raise StandardError, "no input PDB file(s)"
+      raise StandardError("no input PDB file(s)")
 
     # grab PDB file from http://rcsb.org if not a local file
     
@@ -112,7 +115,7 @@ class pdbfile:
       try:
         open(self.files[0],'r').close()
       except:
-        print "downloading %s from http://rcsb.org" % self.files[0]
+        print("downloading %s from http://rcsb.org" % self.files[0])
         fetchstr = "http://www.rcsb.org/pdb/cgi/export.cgi/%s?format=PDB&pdbId=2cpk&compression=None" % self.files[0]
         urllib.urlretrieve(fetchstr,self.files[0])
 
@@ -142,20 +145,20 @@ class pdbfile:
         which,time,flag = self.data.iterator(flag)
         if flag == -1: break
         self.convert(f,which)
-        print >>f,"END"
-        print time,
+        print("END",file=f)
+        print(time,end='')
         sys.stdout.flush()
         n += 1
 
     else:
       for file in self.files:
         f.write(open(file,'r').read())
-        print >>f,"END"
-        print file,
+        print("END",file=f)
+        print(file,end='')
         sys.stdout.flush()
         
     f.close()
-    print "\nwrote %d datasets to %s in PDB format" % (n,file)
+    print("\nwrote %d datasets to %s in PDB format" % (n,file))
 
   # --------------------------------------------------------------------
   # write series of numbered PDB files
@@ -190,7 +193,7 @@ class pdbfile:
         self.convert(f,which)
         f.close()
         
-        print time,
+        print(time,end='')
         sys.stdout.flush()
         n += 1
 
@@ -210,12 +213,12 @@ class pdbfile:
         f = open(file,'w')
         f.write(open(infile,'r').read())
         f.close()
-        print file,
+        print(file,end='')
         sys.stdout.flush()
         
         n += 1
 
-    print "\nwrote %d datasets to %s*.pdb in PDB format" % (n,root)
+    print("\nwrote %d datasets to %s*.pdb in PDB format" % (n,root))
 
   # --------------------------------------------------------------------
   # write a single PDB file
@@ -280,10 +283,10 @@ class pdbfile:
         if self.atomlines.has_key(id):
           (begin,end) = self.atomlines[id]
           line = "%s%8.3f%8.3f%8.3f%s" % (begin,atom[2],atom[3],atom[4],end)
-          print >>f,line,
+          print(line,file=f,end='')
     else:
       for atom in atoms:
         begin = "ATOM %6d %2d   R00     1    " % (atom[0],atom[1])
         middle = "%8.3f%8.3f%8.3f" %  (atom[2],atom[3],atom[4])
         end = "  1.00  0.00    NONE"
-        print >>f,begin+middle+end
+        print(begin+middle+end,file=f)
diff --git a/python/examples/pizza/vmd.py b/python/examples/pizza/vmd.py
index 7a49617b4c..fb5095617a 100644
--- a/python/examples/pizza/vmd.py
+++ b/python/examples/pizza/vmd.py
@@ -6,6 +6,9 @@
 # certain rights in this software.  This software is distributed under 
 # the GNU General Public License.
 
+# for python3 compatibility
+from __future__ import print_function
+
 # vmd tool
 
 # Minimalistic VMD embedding for Pizza.py
@@ -52,7 +55,7 @@ except: PIZZA_VMDDIR = "/usr/local/lib/vmd"
 try: from DEFAULTS import PIZZA_VMDDEV
 except: PIZZA_VMDDEV = "win"
 try: from DEFAULTS import PIZZA_VMDARCH
-except: PIZZA_VMDARCH = "LINUX"
+except: PIZZA_VMDARCH = "LINUXAMD64"
 
 # try these settings for a Mac
 #PIZZA_VMDNAME = "vmd"
@@ -62,8 +65,8 @@ except: PIZZA_VMDARCH = "LINUX"
 
 try: import pexpect
 except: 
-  print "pexpect from http://pypi.python.org/pypi/pexpect", \
-      "is required for vmd tool"
+  print("pexpect from http://pypi.python.org/pypi/pexpect", \
+      "is required for vmd tool")
   raise
 
 # Class definition
@@ -109,7 +112,7 @@ class vmd:
       self.VMD.sendline(command)
       self.VMD.expect('vmd >')
       if self.debugme:
-        print "call+result:"+self.VMD.before
+        print("call+result:"+self.VMD.before)
     return
     
   # --------------------------------------------------------------------
@@ -127,9 +130,9 @@ class vmd:
   # turn on debugging info
   def debug(self,status=True):
     if status and not self.debugme:
-      print 'Turning vmd.py debugging ON.'
+      print('Turning vmd.py debugging ON.')
     if not status and self.debugme:
-      print 'Turning vmd.py debugging OFF.'
+      print('Turning vmd.py debugging OFF.')
     self.debugme = status
 
   # --------------------------------------------------------------------
@@ -141,14 +144,14 @@ class vmd:
       try:
         command = raw_input("vmd > ")
       except EOFError:
-        print "(EOF)"
+        print("(EOF)")
         self.__call__('menu main off')
         return
       if command == "quit" or command == "exit":
         self.__call__('menu main off')
         return
       if command == "gopython":
-        print "gopython not supported here"
+        print("gopython not supported here")
         continue
       self.__call__(command)