Fix __len__ in CIFAR10Sequence example in Python2
diff --git a/keras/utils/data_utils.py b/keras/utils/data_utils.py
index c5a6d79359b..4398c1d20d8 100644
--- a/keras/utils/data_utils.py
+++ b/keras/utils/data_utils.py
@@ -315,7 +315,6 @@ class Sequence(object):
         from skimage.io import imread
         from skimage.transform import resize
         import numpy as np
-        import math
 
         # Here, `x_set` is list of path to the images
         # and `y_set` are the associated classes.
@@ -327,7 +326,7 @@ def __init__(self, x_set, y_set, batch_size):
                 self.batch_size = batch_size
 
             def __len__(self):
-                return math.ceil(len(self.x) / self.batch_size)
+                return np.ceil(len(self.x) / float(self.batch_size))
 
             def __getitem__(self, idx):
                 batch_x = self.x[idx * self.batch_size:(idx + 1) * self.batch_size]

Fix PR https://github.com/fchollet/keras/pull/8275 for Python2.