Tensorflow RuntimeError:\uuuuIter\uuuuuu（）仅在tf.function内部或启用了急切执行时受支持

我是tensorflow的新手，正在努力学习它。尝试在Tensorflow 2.2.0中运行估算器线性分类器

导入所有模块并读入TFR记录

定义解析函数

定义要传入估计器的输入函数

初始化估计器

运行以下代码会出现错误：

Traceback (most recent call last):
  File "linear_classification.py", line 42, in <module>
    input_fn = input_fn
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 349, in train
    loss = self._train_model(input_fn, hooks, saving_listeners)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1182, in _train_model
    return self._train_model_default(input_fn, hooks, saving_listeners)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1208, in _train_model_default
    self._get_features_and_labels_from_input_fn(input_fn, ModeKeys.TRAIN))
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1044, in _get_features_and_labels_from_input_fn
    self._call_input_fn(input_fn, mode))
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1137, in _call_input_fn
    return input_fn(**kwargs)
  File "linear_classification.py", line 31, in input_fn
    iterator = iter(dataset)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py", line 406, in __iter__
    raise RuntimeError("__iter__() is only supported inside of tf.function "
RuntimeError: __iter__() is only supported inside of tf.function or when eager execution is enabled.

---

这是我的第一个StackOverflow问题，如果我没有遵循任何指导原则或规则，请原谅。非常感谢您的帮助。谢谢。

所以我发现问题是。错误状态为

RuntimeError:\uuuu iter\uuuu（）仅在tf.function内部受支持，或者在启用了急切执行时受支持

。我将

@tf.function

放在我的

input\u fn（）上方。因此，现在我的
input\u fn（）
如下所示：

@tf.function
def input_fn():
    dataset = tf.data.TFRecordDataset(filenames = filenames)
    
    dataset = dataset.map(_parse_function)
    iterator = iter(dataset)
    next_element = iterator.get_next()
    return next_element

通过阅读TensorFlow文档，我能够跟踪问题：

def input_fn():
    dataset = tf.data.TFRecordDataset(filenames = filenames)
    
    dataset = dataset.map(_parse_function)
    iterator = iter(dataset)
    next_element = iterator.get_next()
    return next_element

feature_columns = [
    tf.feature_column.numeric_column('Age'),
    tf.feature_column.numeric_column('EstimatedSalary')
]

estimator = tf.estimator.LinearClassifier(feature_columns = feature_columns)
estimator.train(
    input_fn = input_fn
)

Traceback (most recent call last):
  File "linear_classification.py", line 42, in <module>
    input_fn = input_fn
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 349, in train
    loss = self._train_model(input_fn, hooks, saving_listeners)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1182, in _train_model
    return self._train_model_default(input_fn, hooks, saving_listeners)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1208, in _train_model_default
    self._get_features_and_labels_from_input_fn(input_fn, ModeKeys.TRAIN))
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1044, in _get_features_and_labels_from_input_fn
    self._call_input_fn(input_fn, mode))
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1137, in _call_input_fn
    return input_fn(**kwargs)
  File "linear_classification.py", line 31, in input_fn
    iterator = iter(dataset)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py", line 406, in __iter__
    raise RuntimeError("__iter__() is only supported inside of tf.function "
RuntimeError: __iter__() is only supported inside of tf.function or when eager execution is enabled.

/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tensorflow/python/data/ops/dataset_ops.py

@tf.function
def input_fn():
    dataset = tf.data.TFRecordDataset(filenames = filenames)
    
    dataset = dataset.map(_parse_function)
    iterator = iter(dataset)
    next_element = iterator.get_next()
    return next_element