python3 compatibility

code/cube.py

@@ -46,6 +46,7 @@
 
 """
 
+from __future__ import print_function
 import numpy as np
 import matplotlib.pyplot as plt
 from matplotlib.patches import Rectangle
@@ -145,7 +146,7 @@ def move(self, f, l, d):
                 self.stickers[i] = np.rot90(self.stickers[i], 3)
             if l == self.N - 1:
                 self.stickers[i2] = np.rot90(self.stickers[i2], 1)
-        print "moved", f, l, len(ds)
+        print("moved", f, l, len(ds))
         return None
 
     def _rotate(self, args):

code/simple_cube.py

@@ -133,13 +133,17 @@ class CubeAxes(Axes):
     The cube has side-length 2, and the observer is a distance zloc away
     along the z-axis.
     """
-    face = np.array([[1, 1], [1, -1], [-1, -1], [-1, 1], [1, 1]])
-    faces = np.array([np.hstack([face[:, :i],
+
+    def faces():
+        face = np.array([[1, 1], [1, -1], [-1, -1], [-1, 1], [1, 1]])
+        return np.array([np.hstack([face[:, :i],
                                  np.ones((5, 1)),
                                  face[:, i:]]) for i in range(3)] +
                      [np.hstack([face[:, :i],
                                  -np.ones((5, 1)),
                                  face[:, i:]]) for i in range(3)])
+    faces = faces()
+
     stickercolors = ["#ffffff", "#00008f", "#ff6f00",
                      "#ffcf00", "#009f0f", "#cf0000"]