这是一个玩具代码,它复制了我在尝试使用生成器动态生成/提供训练数据时遇到的问题。
def makeRand():
yield np.random.rand(1)
dataset = tf.data.Dataset.from_generator(makeRand, (tf.float32))
iterator = tf.contrib.data.Iterator.from_structure(tf.float32, tf.TensorShape([]))
next_x = iterator.get_next()
init_op = iterator.make_initializer(dataset)
with tf.Session() as sess:
sess.run(init_op)
a = sess.run(next_x)
print(a)
a = sess.run(next_x)
print(a)
跟踪看起来像:
Traceback (most recent call last):
File “test_iterator_gen.py", line 31, in <module>
a = sess.run(next_x)
tensorflow.python.framework.errors_impl.OutOfRangeError: End of sequence
[[Node: IteratorGetNext = IteratorGetNext[output_shapes=[[]], output_types=[DT_FLOAT], _device="/job:localhost/replica:0/task:0/device:CPU:0"](Iterator)]]
Caused by op 'IteratorGetNext', defined at:
File "test_iterator_gen.py", line 23, in <module>
next_x = iterator.get_next()
OutOfRangeError (see above for traceback): End of sequence
[[Node: IteratorGetNext = IteratorGetNext[output_shapes=[[]], output_types=[DT_FLOAT], _device="/job:localhost/replica:0/task:0/device:CPU:0"](Iterator)]]