title: AttributeError: module 'tensorflow.python.training.experimental.mixed_precision' has no attribute '_register_wrapper_optimizer_cls'
body: <p>I am using Keras to implement a neural network. But when I use <code>model = Sequential()</code>, I get the following error:</p>
  <pre><code>AttributeError                            Traceback (most recent call last)
  &lt;ipython-input-31-fa9fd3b0e211&gt; in &lt;module&gt;
        8 
        9 # Create the model
  ---&gt; 10 model = Sequential()
       11 model.add(Dropout(0.1), input_shape=(128,))
       12 model.add(Dense(256, activation='relu', kernel_initializer='he_uniform'))
  
  /usr/local/lib/python3.6/dist-packages/tensorflow/python/keras/utils/version_utils.py in __new__(cls, *args, **kwargs)
       55     use_v2 = should_use_v2()
       56     cls = swap_class(cls, training.Model, training_v1.Model, use_v2)  # pylint: disable=self-cls-assignment
  ---&gt; 57     return super(ModelVersionSelector, cls).__new__(cls)
       58 
       59 
  
  /usr/local/lib/python3.6/dist-packages/tensorflow/python/util/lazy_loader.py in __getattr__(self, item)
       60 
       61   def __getattr__(self, item):
  ---&gt; 62     module = self._load()
       63     return getattr(module, item)
       64 
  
  /usr/local/lib/python3.6/dist-packages/tensorflow/python/util/lazy_loader.py in _load(self)
       43     &quot;&quot;&quot;Load the module and insert it into the parent's globals.&quot;&quot;&quot;
       44     # Import the target module and insert it into the parent's namespace
  ---&gt; 45     module = importlib.import_module(self.__name__)
       46     self._parent_module_globals[self._local_name] = module
       47 
  
  /usr/lib/python3.6/importlib/__init__.py in import_module(name, package)
      124                 break
      125             level += 1
  --&gt; 126     return _bootstrap._gcd_import(name[level:], package, level)
      127 
      128 
  
  /usr/lib/python3.6/importlib/_bootstrap.py in _gcd_import(name, package, level)
  
  /usr/lib/python3.6/importlib/_bootstrap.py in _find_and_load(name, import_)
  
  /usr/lib/python3.6/importlib/_bootstrap.py in _find_and_load_unlocked(name, import_)
  
  /usr/lib/python3.6/importlib/_bootstrap.py in _load_unlocked(spec)
  
  /usr/lib/python3.6/importlib/_bootstrap_external.py in exec_module(self, module)
  
  /usr/lib/python3.6/importlib/_bootstrap.py in _call_with_frames_removed(f, *args, **kwds)
  
  /usr/local/lib/python3.6/dist-packages/tensorflow/python/keras/engine/base_layer_v1.py in &lt;module&gt;
       48 from tensorflow.python.keras.engine import input_spec
       49 from tensorflow.python.keras.mixed_precision import autocast_variable
  ---&gt; 50 from tensorflow.python.keras.mixed_precision import loss_scale_optimizer
       51 from tensorflow.python.keras.mixed_precision import policy
       52 from tensorflow.python.keras.saving.saved_model import layer_serialization
  
  /usr/local/lib/python3.6/dist-packages/tensorflow/python/keras/mixed_precision/loss_scale_optimizer.py in &lt;module&gt;
     1152 
     1153 # pylint: disable=protected-access
  -&gt; 1154 mixed_precision._register_wrapper_optimizer_cls(optimizer_v2.OptimizerV2,
     1155                                                 LossScaleOptimizerV1)
     1156 
  
  AttributeError: module 'tensorflow.python.training.experimental.mixed_precision' has no attribute '_register_wrapper_optimizer_cls'
  </code></pre>
  <p>I am relatively new to deep learning. Any help would be appreciated. Thank you!</p>