ZeroDivisionError: float division by zero

[SeekPoint]

rzai@rzai00:/prj/FM_FTRL$ python runmodel_dropout_example.py
Start Training:
Epoch 0 count: 0 Progressive Loss: 0.693145
Epoch 0 count: 1000000 Progressive Loss: 0.384036
Epoch 0 count: 2000000 Progressive Loss: 0.382631
Epoch 0 count: 3000000 Progressive Loss: 0.396255
Epoch 0 count: 4000000 Progressive Loss: 0.401109
Epoch 0 count: 5000000 Progressive Loss: 0.400137
Epoch 0 count: 6000000 Progressive Loss: 0.395026
Epoch 0 count: 7000000 Progressive Loss: 0.387025
Epoch 0 count: 8000000 Progressive Loss: 0.382029
Epoch 0 count: 9000000 Progressive Loss: 0.384626
Traceback (most recent call last):
File "runmodel_dropout_example.py", line 76, in
print("Epoch %d finished.\tvalidation loss: %f\telapsed time: %s" % (e, cvLoss / cvCount, str(datetime.now() - start)))
ZeroDivisionError: float division by zero
rzai@rzai00:/prj/FM_FTRL$