I defined a placeholder during graph construction time like this,
input_ = tf.placeholder(tf.float32, shape=(batch_size, None, 3,1))
and then I want operation like this
shape = input_.get_shape().as_list()
stride_1 = np.floor(float(shape[1] / 5)).astype(np.int32)
But it is showing
TypeError: unsupported operand type(s) for /: 'NoneType' and 'int'