def mean_absolute_percentage_error(y_true, y_pred):
    diff = K.abs(K.clip(K.abs(y_true), K.epsilon(), np.inf) / (y_true - y_pred))
    return 100. * K.mean(diff)
dataset/ETHPy150Open fchollet/keras/keras/metrics.py/mean_absolute_percentage_error/swapped operands of `/`