diff --git a/GPy/inference/latent_function_inference/var_dtc_parallel.py b/GPy/inference/latent_function_inference/var_dtc_parallel.py
index c546a4a1..4b884d4c 100644
--- a/GPy/inference/latent_function_inference/var_dtc_parallel.py
+++ b/GPy/inference/latent_function_inference/var_dtc_parallel.py
@@ -170,7 +170,7 @@ class VarDTC_minibatch(LatentFunctionInference):
         Kmm = kern.K(Z).copy()
         diag.add(Kmm, self.const_jitter)
         if not np.isfinite(Kmm).all():
-            print Kmm
+            print(Kmm)
         Lm = jitchol(Kmm)
 
         LmInvPsi2LmInvT = backsub_both_sides(Lm,psi2_full,transpose='right')
diff --git a/GPy/testing/mapping_tests.py b/GPy/testing/mapping_tests.py
index 2e32dad3..2ff0e2d8 100644
--- a/GPy/testing/mapping_tests.py
+++ b/GPy/testing/mapping_tests.py
@@ -26,11 +26,6 @@ class MappingGradChecker(GPy.core.Model):
         self.mapping.update_gradients(self.dL_dY, self.X)
 
 
-
-
-
-
-
 class MappingTests(unittest.TestCase):
 
     def test_kernelmapping(self):
@@ -68,5 +63,5 @@ class MappingTests(unittest.TestCase):
 
 
 if __name__ == "__main__":
-    print "Running unit tests, please be (very) patient..."
+    print("Running unit tests, please be (very) patient...")
     unittest.main()
diff --git a/GPy/util/choleskies.py b/GPy/util/choleskies.py
index b64beae1..37ac7211 100644
--- a/GPy/util/choleskies.py
+++ b/GPy/util/choleskies.py
@@ -2,8 +2,13 @@
 # Licensed under the GNU GPL version 3.0
 
 import numpy as np
-from scipy import weave
 from . import linalg
+from .config import config
+
+try:
+    from scipy import weave
+except ImportError:
+    config.set('weave', 'working', 'False')
 
 def safe_root(N):
     i = np.sqrt(N)
@@ -12,12 +17,13 @@ def safe_root(N):
         raise ValueError("N is not square!")
     return j
 
-def flat_to_triang(flat):
+def _flat_to_triang_weave(flat):
     """take a matrix N x D and return a M X M x D array where
 
     N = M(M+1)/2
 
     the lower triangluar portion of the d'th slice of the result is filled by the d'th column of flat.
+    This is the weave implementation
     """
     N, D = flat.shape
     M = (-1 + safe_root(8*N+1))/2
@@ -41,7 +47,24 @@ def flat_to_triang(flat):
     weave.inline(code, ['flat', 'ret', 'D', 'M'])
     return ret
 
-def triang_to_flat(L):
+def _flat_to_triang_pure(flat_mat):
+    N, D = flat_mat.shape
+    M = (-1 + safe_root(8*N+1))//2
+    ret = np.zeros((M, M, D))
+    count = 0
+    for m in range(M):
+        for mm in range(m+1):
+            for d in range(D):
+              ret.flat[d + m*D*M + mm*D] = flat_mat.flat[count];
+              count = count+1
+    return ret
+
+if config.getboolean('weave', 'working'):
+	flat_to_triang =  _flat_to_triang_weave
+else:
+        flat_to_triang =  _flat_to_triang_pure
+
+def _triang_to_flat_weave(L):
     M, _, D = L.shape
 
     L = np.ascontiguousarray(L) # should do nothing if L was created by flat_to_triang
@@ -65,6 +88,24 @@ def triang_to_flat(L):
     weave.inline(code, ['flat', 'L', 'D', 'M'])
     return flat
 
+def _triang_to_flat_pure(L):
+    M, _, D = L.shape
+
+    N = M*(M+1)//2
+    flat = np.empty((N, D))
+    count = 0;
+    for m in range(M):
+        for mm in range(m+1):
+            for d in range(D):
+                flat.flat[count] = L.flat[d + m*D*M + mm*D];
+                count = count +1
+    return flat
+
+if config.getboolean('weave', 'working'):
+    triang_to_flat =  _triang_to_flat_weave
+else:
+    triang_to_flat =  _triang_to_flat_pure
+
 def triang_to_cov(L):
     return np.dstack([np.dot(L[:,:,i], L[:,:,i].T) for i in range(L.shape[-1])])
 
diff --git a/GPy/util/linalg.py b/GPy/util/linalg.py
index ec83810f..8ac5418f 100644
--- a/GPy/util/linalg.py
+++ b/GPy/util/linalg.py
@@ -102,14 +102,14 @@ def jitchol(A, maxtries=5):
         num_tries = 1
         while num_tries <= maxtries and np.isfinite(jitter):
             try:
-                print jitter
+                print(jitter)
                 L = linalg.cholesky(A + np.eye(A.shape[0]) * jitter, lower=True)
                 return L
             except:
                 jitter *= 10
             finally:
                 num_tries += 1
-        raise linalg.LinAlgError, "not positive definite, even with jitter."
+        raise linalg.LinAlgError("not positive definite, even with jitter.")
     import traceback
     try: raise
     except: