def __call__(self, inputs, *args, **kwargs):
    """Wraps `call`, applying pre- and post-processing steps.

    Arguments:
      inputs: input tensor(s).
      *args: additional positional arguments to be passed to `self.call`.
      **kwargs: additional keyword arguments to be passed to `self.call`.
        **Note**: kwarg `scope` is reserved for use by the layer.
    Returns:
      Output tensor(s).
    """
    self._set_scope(kwargs.pop('scope', None))

    # Ensure the Layer, if being reused, is working with inputs from
    # the same graph as where it was created.
    try:
      ops._get_graph_from_inputs(nest.flatten(inputs), graph=self.graph)  # pylint: disable=protected-access
    except ValueError as e:
      raise ValueError('Input graph and Layer graph are not the same: %s' % e)

    with vs.variable_scope(self._scope,
                           reuse=self.built or self._reuse) as scope:
      with ops.name_scope(scope.original_name_scope):
        if not self.built:
          # Check input assumptions set before layer building, e.g. input rank.
          self._assert_input_compatibility(inputs)
          input_list = [
              ops.convert_to_tensor(x, name='input')
              for x in nest.flatten(inputs)]
          input_shapes = [x.get_shape() for x in input_list]
          if len(input_shapes) == 1:
            self.build(input_shapes[0])
          else:
            self.build(input_shapes)
        if 'scope' in tf_inspect.getargspec(self.call).args:
          kwargs['scope'] = scope
        # Check input assumptions set after layer building, e.g. input shape.
        self._assert_input_compatibility(inputs)
        outputs = self.call(inputs, *args, **kwargs)

        # Apply activity regularization.
        # Note that it should be applied every time the layer creates a new
        # output, since it is output-specific.
        if hasattr(self, 'activity_regularizer') and self.activity_regularizer:
          output_list = _to_list(outputs)
          for output in output_list:
            with ops.name_scope('ActivityRegularizer'):
              activity_regularization = self.activity_regularizer(output)
            self.add_loss(activity_regularization)
            _add_elements_to_collection(
                activity_regularization, ops.GraphKeys.REGULARIZATION_LOSSES)

    # Update global default collections.
    _add_elements_to_collection(self.updates, ops.GraphKeys.UPDATE_OPS)
    self.built = True
    return outputs

def get_graph_from_inputs(op_input_list, graph=None):
  """Returns the appropriate graph to use for the given inputs.

  1. If `graph` is provided, we validate that all inputs in `op_input_list` are
     from the same graph.
  2. Otherwise, we attempt to select a graph from the first Operation- or
     Tensor-valued input in `op_input_list`, and validate that all other
     such inputs are in the same graph.
  3. If the graph was not specified and it could not be inferred from
     `op_input_list`, we attempt to use the default graph.

  Args:
    op_input_list: A list of inputs to an operation, which may include `Tensor`,
      `Operation`, and other objects that may be converted to a graph element.
    graph: (Optional) The explicit graph to use.

  Raises:
    TypeError: If `op_input_list` is not a list or tuple, or if graph is not a
      Graph.
    ValueError: If a graph is explicitly passed and not all inputs are from it,
      or if the inputs are from multiple graphs, or we could not find a graph
      and there was no default graph.

  Returns:
    The appropriate graph to use for the given inputs.
  """
  # pylint: disable=protected-access
  return ops._get_graph_from_inputs(op_input_list, graph)

def variable_op_scope(values, name, default_name, initializer=None,
                      regularizer=None):
  """Returns a context manager for defining an op that creates variables.

  This context manager validates that the given `values` are from the
  same graph, ensures that that graph is the default graph, and pushes a
  name scope and a variable scope.

  If `name` is not None, it is used as is in the variable scope. If `name`
  is None, then `default_name` is used.  In that case, if the same name has been
  previously used in the same scope, it will made unique be appending `_N` to
  it.

  This is intended to be used when defining generic ops and so reuse is always
  inherited.

  For example, to define a new Python op called `my_op_with_vars`:

  ```python
  def my_op_with_vars(a, b, name=None):
    with tf.variable_op_scope([a, b], name, "MyOp") as scope:
      a = tf.convert_to_tensor(a, name="a")
      b = tf.convert_to_tensor(b, name="b")
      c = tf.get_variable('c')
      # Define some computation that uses `a`, `b`, and `c`.
      return foo_op(..., name=scope)
  ```

  Args:
    values: The list of `Tensor` arguments that are passed to the op function.
    name: The name argument that is passed to the op function, this name is not
      uniquified in the variable scope.
    default_name: The default name to use if the `name` argument is `None`, this
      name will be uniquified.
    initializer: A default initializer to pass to variable scope.
    regularizer: default regularizer for variables within this scope.

  Returns:
    A context manager for use in defining a Python op.

  Raises:
    ValueError: when trying to reuse within a create scope, or create within
      a reuse scope, or if reuse is not `None` or `True`.
    TypeError: when the types of some arguments are not appropriate.
  """
  if default_name is None:
    raise TypeError("default_name cannot be None")
  g = ops._get_graph_from_inputs(values)  # pylint: disable=protected-access
  with g.as_default():
    if name:
      with variable_scope(name, initializer=initializer,
                          regularizer=regularizer) as vs:
        yield vs
    else:
      with ops.name_scope(default_name) as scope:
        count = len(default_name.split("/"))
        scoped_name = "/".join(scope.split("/")[-count - 1:-1])
        with _pure_variable_scope(scoped_name, initializer=initializer,
                                  regularizer=regularizer) as vs:
          yield vs

def graph_zeros_like(tensor):
  """Graph-only version of tf.zeros_like(), for internal use only."""
  g = ops._get_graph_from_inputs([tensor])  # pylint: disable=protected-access
  with g.as_default(), ops.name_scope(None, "zeros_like", [tensor]) as name:
    tensor = ops.convert_to_tensor(tensor, name="tensor")
    dtype = tensor.dtype.base_dtype
    dtype_value = attr_value_pb2.AttrValue(type=dtype.as_datatype_enum)
    op = g.create_op("ZerosLike", [tensor], [dtype], input_types=[dtype],
                     attrs={"T": dtype_value}, name=name)
  result, = op.outputs
  return result

  def _distributed_apply(self, distribution, grads_and_vars, name):
    """`apply_gradients` using a `DistributionStrategy`."""
    reduced_grads = distribution.extended.batch_reduce_to(
        ds_reduce_util.ReduceOp.SUM, grads_and_vars)
    var_list = [v for _, v in grads_and_vars]
    grads_and_vars = zip(reduced_grads, var_list)

    def apply_grad_to_update_var(var, grad):
      """Apply gradient to variable."""
      if isinstance(var, ops.Tensor):
        raise NotImplementedError("Trying to update a Tensor ", var)
      if isinstance(grad, ops.IndexedSlices):
        if var.constraint is not None:
          raise RuntimeError(
              "Cannot use a constraint function on a sparse variable.")
        return self._resource_apply_sparse_duplicate_indices(
            grad.values, var, grad.indices)
      update_op = self._resource_apply_dense(grad, var)
      if var.constraint is not None:
        with ops.control_dependencies([update_op]):
          return var.assign(var.constraint(var))
      else:
        return update_op

    update_ops = []
    with backend.name_scope(name or self._name):
      for grad, var in grads_and_vars:
        scope_name = ("" if ops.executing_eagerly_outside_functions() else
                      "_" + var.op.name)
        with backend.name_scope("update" + scope_name):
          update_ops.extend(
              distribution.extended.update(
                  var, apply_grad_to_update_var, args=(grad,), group=False))

      any_symbolic = any(isinstance(i, ops.Operation) or
                         tf_utils.is_symbolic_tensor(i) for i in update_ops)
      if not context.executing_eagerly() or any_symbolic:
        # If the current context is graph mode or any of the update ops are
        # symbolic then the step update should be carried out under a graph
        # context. (eager updates execute immediately)
        with ops._get_graph_from_inputs(update_ops).as_default():  # pylint: disable=protected-access
          with ops.control_dependencies(update_ops):
            return self._iterations.assign_add(1).op

      return self._iterations.assign_add(1)

  def apply_op(self, op_type_name, name=None, **keywords):
    # pylint: disable=g-doc-args
    """Add a node invoking a registered Op to a graph.

    Example usage:
       # input1 and input2 can be Tensors or anything ops.convert_to_tensor()
       # will convert to a Tensor.
       op_def_library.apply_op("op", input1=input1, input2=input2)
       # Can specify a node name.
       op_def_library.apply_op("op", input1=input1, name="node_name")
       # Must use keyword arguments, with the names specified in the OpDef.
       op_def_library.apply_op("op", input_name=input, attr_name=attr)

    All attrs must either be inferred from an input or specified.
    (If inferred, the attr must not be specified.)  If an attr has a default
    value specified in the Op's OpDef, then you may pass None as the value
    of that attr to get the default.

    Args:
      op_type_name: string. Must match the name field of a registered Op.
      name: string. Optional name of the created op.
      **keywords: input Tensor and attr arguments specified by name,
        and optional parameters to pass when constructing the Operation.

    Returns:
      The Tensor(s) representing the output of the operation, or the Operation
      itself if there are no outputs.

    Raises:
      RuntimeError: On some errors.
      TypeError: On some errors.
      ValueError: On some errors.
    """
    op_info = self._ops.get(op_type_name, None)
    if op_info is None:
      raise RuntimeError("Unrecognized Op name " + op_type_name)
    op_def = op_info.op_def

    # Determine the graph context.
    try:
      # Need to flatten all the arguments into a list.
      # pylint: disable=protected-access
      g = ops._get_graph_from_inputs(_Flatten(keywords.values()))
      # pyline: enable=protected-access
    except AssertionError as e:
      raise RuntimeError(
          "Cannot determine graph for Op '%s' due to: %s"
          % (op_type_name, e.message))

    # Default name if not specified.
    if name is None:
      name = op_type_name

    # Check for deprecation
    deprecation_version = op_def.deprecation.version
    if deprecation_version:
      producer = g.graph_def_versions.producer
      if producer >= deprecation_version:
        raise NotImplementedError(
            ("Op %s is not available in GraphDef version %d. "
             "It has been removed in version %d. %s.") %
            (op_type_name, producer, deprecation_version,
             op_def.deprecation.explanation))

    # Fill in the list of default types for all "type" attrs.  This
    # will be used to choose a preferred dtype to convert to in the
    # absence of input type information.
    #
    # TODO(b/31302892): Currently the defaults don't work in the right
    # way if you have two inputs, one of whose type resolution depends
    # on the other.  Handling this will require restructuring this code
    # significantly.
    default_type_attr_map = {}
    for attr_def in op_def.attr:
      if attr_def.type != "type":
        continue
      key = attr_def.name
      if attr_def.HasField("default_value"):
        default_type_attr_map[key] = dtypes.as_dtype(
            attr_def.default_value.type)

    # Requires that op_def has passed validation (using the C++
    # ValidateOpDef() from ../framework/op_def_util.h).
    attrs = {}
    inputs = []
    input_types = []
    with g.as_default(), ops.name_scope(name) as scope:

      # Perform input type inference
      inferred_from = {}
      for input_arg in op_def.input_arg:
        input_name = input_arg.name
        if input_name in keywords:
          values = keywords.pop(input_name)
        elif input_name + "_" in keywords:
          # Handle the case where the name is a keyword or built-in
          # for Python so we use the name + _ instead.
          input_name += "_"
          values = keywords.pop(input_name)
        else:
#.........这里部分代码省略.........

  def __call__(self, inputs, *args, **kwargs):
    """Wraps `call`, applying pre- and post-processing steps.

    Arguments:
      inputs: input tensor(s).
      *args: additional positional arguments to be passed to `self.call`.
      **kwargs: additional keyword arguments to be passed to `self.call`.
        **Note**: kwarg `scope` is reserved for use by the layer.

    Returns:
      Output tensor(s).

    Note:
      - If the layer's `call` method takes a `scope` keyword argument,
        this argument will be automatically set to the current variable scope.
      - If the layer's `call` method takes a `mask` argument (as some Keras
        layers do), its default value will be set to the mask generated
        for `inputs` by the previous layer (if `input` did come from
        a layer that generated a corresponding mask, i.e. if it came from
        a Keras layer with masking support.

    Raises:
      ValueError: if the layer's `call` method returns None (an invalid value).
    """
    scope = kwargs.pop('scope', None)

    if self._keras_style:
      if scope is not None:
        raise ValueError(
            'scope argument not allowed when keras style layers are enabled, '
            'but saw: {}'.format(scope))
      return super(Layer, self).__call__(inputs, *args, **kwargs)

    self._set_scope(scope)

    if not context.executing_eagerly():
      try:
        # Set layer's "graph" at build time
        self._graph = ops._get_graph_from_inputs(nest.flatten(inputs),  # pylint: disable=protected-access
                                                 graph=self._graph)
      except ValueError as e:
        raise ValueError('Input graph and Layer graph are not the same: %s' % e)

    if self.built:
      try:
        # Some classes which inherit from Layer do not use its constructor, so
        # rather than initializing to None we check for an AttributeError.
        scope_context_manager = self._always_reuse_variable_scope
      except AttributeError:
        # From this point we will always set reuse=True, so create a "final"
        # variable scope with this setting. We avoid re-creating variable scopes
        # after this point as an optimization.
        self._always_reuse_variable_scope = vs.variable_scope(
            self._scope, reuse=True, auxiliary_name_scope=False)
        scope_context_manager = self._always_reuse_variable_scope
    else:
      scope_context_manager = vs.variable_scope(
          self._scope, reuse=self._reuse, auxiliary_name_scope=False)

    with scope_context_manager as scope:
      self._current_scope = scope

      try:
        call_has_scope_arg = self._call_has_scope_arg
      except AttributeError:
        self._call_fn_args = function_utils.fn_args(self.call)
        self._call_has_scope_arg = 'scope' in self._call_fn_args
        call_has_scope_arg = self._call_has_scope_arg
      if call_has_scope_arg:
        kwargs['scope'] = scope

      # Actually call layer
      outputs = super(Layer, self).__call__(inputs, *args, **kwargs)

    if not context.executing_eagerly():
      # Update global default collections.
      _add_elements_to_collection(self.updates, ops.GraphKeys.UPDATE_OPS)
    return outputs

  def __call__(self, inputs, *args, **kwargs):
    """Wraps `call`, applying pre- and post-processing steps.

    Arguments:
      inputs: input tensor(s).
      *args: additional positional arguments to be passed to `self.call`.
      **kwargs: additional keyword arguments to be passed to `self.call`.
        **Note**, the kwarg 'scope' is reserved for use by the Layer.

    Returns:
      Output tensor(s).
    """
    scope = kwargs.pop('scope', None)

    # Define a custom getter to override tf.get_variable when creating layer
    # variables. The current custom getter is nested by the variable scope.
    def variable_getter(getter, name, shape, dtype=None, initializer=None,
                        regularizer=None, trainable=True, **getter_kwargs):
      return self._add_variable(
          name, shape, initializer=initializer, regularizer=regularizer,
          dtype=dtype, trainable=trainable,
          variable_getter=functools.partial(getter, **getter_kwargs))

    if not self._built and self._scope is None:
      # If constructed with _scope=None, lazy setting of scope.
      if self._reuse:
        self._scope = next(vs.variable_scope(
            scope if scope is not None else self._base_name).gen)
      else:
        self._scope = next(vs.variable_scope(
            scope, default_name=self._base_name).gen)
      self._name = self._scope.name

    # Build (if necessary) and call the layer, inside a variable
    # scope.
    with vs.variable_scope(self._scope,
                           reuse=True if self._built else self._reuse,
                           custom_getter=variable_getter) as scope:
      # Ensure the Layer, if being reused, is working with inputs from
      # the same graph as where it was created.
      try:
        ops._get_graph_from_inputs(nest.flatten(inputs), graph=self.graph)  # pylint: disable=protected-access
      except ValueError as e:
        raise ValueError("Inputs' and Layer's graphs are not the same: %s" % e)

      with ops.name_scope(scope.original_name_scope):
        if not self.built:
          input_list = [
              ops.convert_to_tensor(x, name='input')
              for x in nest.flatten(inputs)]
          input_shapes = [x.get_shape() for x in input_list]
          if len(input_shapes) == 1:
            self.build(input_shapes[0])
          else:
            self.build(input_shapes)
          self._built = True
        outputs = self.call(inputs, *args, **kwargs)

        # Apply activity regularization.
        # Note that it should be applied every time the layer creates a new
        # output, since it is output-specific.
        if hasattr(self, 'activity_regularizer') and self.activity_regularizer:
          output_list = _to_list(outputs)
          for output in output_list:
            with ops.name_scope('ActivityRegularizer'):
              activity_regularization = self.activity_regularizer(output)
            self._losses.append(activity_regularization)
            _add_elements_to_collection(
                activity_regularization, ops.GraphKeys.REGULARIZATION_LOSSES)

    # Update global default collections.
    _add_elements_to_collection(self.updates, ops.GraphKeys.UPDATE_OPS)
    return outputs

  def apply_op(self, op_type_name, g=None, name=None, **keywords):
    # pylint: disable=g-doc-args
    """Add a node invoking a registered Op to a graph.

    Config proto extensions must be provided via the 'ext' keyword argument.
    Example usage:
       # input1 and input2 can be Tensors or anything ops.convert_to_tensor()
       # will convert to a Tensor.
       op_def_library.apply_op("op", input1=input1, input2=input2)
       # If none of the inputs are Tensors and your session doesn't have a
       # default graph, you will have to specify the graph.
       op_def_library.apply_op("op", input1=input1, g=g)
       # Can specify a node name.
       op_def_library.apply_op("op", input1=input1, name="node_name")
       # Must use keyword arguments, with the names specified in the OpDef.
       op_def_library.apply_op("op", input_name=input, attr_name=attr)

    All attrs must either be inferred from an input or specified.
    (If inferred, the attr must not be specified.)  If an attr has a default
    value specified in the Op's OpDef, then you may pass None as the value
    of that attr to get the default.

    Args:
      op_type_name: string. Must match the name field of a registered Op.
      g: The graph context (optional)
      name: string. Optional name of the created op.
      **keywords: input Tensor and attr arguments specified by name,
        and optional parameters to pass when constructing the Operation.

    Returns:
      The Tensor(s) representing the output of the operation, or the Operation
      itself if there are no outputs.

    Raises:
      RuntimeError: On some errors.
      TypeError: On some errors.
      ValueError: On some errors.
    """
    op_info = self._ops.get(op_type_name, None)
    if op_info is None:
      raise RuntimeError("Unrecognized Op name " + op_type_name)
    op_def = op_info.op_def

    # Determine the graph context.
    try:
      # Need to flatten all the arguments into a list.
      # pylint: disable=protected-access
      g = ops._get_graph_from_inputs(_Flatten(keywords.values()), graph=g)
      # pyline: enable=protected-access
    except AssertionError as e:
      raise RuntimeError(
          "Need to specify g=graph to Op '%s' (could not determine graph due "
          "to: %s)" % (op_type_name, e.message))

    # Default name if not specified.
    if name is None:
      name = op_type_name

    # Requires that op_def has passed validation (using the C++
    # ValidateOpDef() from ../framework/op_def_util.h).
    attrs = {}
    inputs = []
    input_types = []
    with g.as_default(), ops.name_scope(name) as scope:

      # Perform input type inference
      inferred_from = {}
      for input_arg in op_def.input_arg:
        input_name = input_arg.name
        if input_name in keywords:
          values = keywords.pop(input_name)
        elif input_name + "_" in keywords:
          # Handle the case where the name is a keyword or built-in
          # for Python so we use the name + _ instead.
          input_name += "_"
          values = keywords.pop(input_name)
        else:
          raise TypeError("No argument for input " + input_name)

        # Goals:
        # * Convert values to Tensors if it contains constants.
        # * Verify that values is a list if that matches the input_arg's
        #   type.
        # * If the input_arg's type is determined by attrs, either set
        #   those attrs and validate those attr values are legal (if
        #   they have not yet been set) or validate the input matches
        #   the type indicated by the attrs (if they have already been
        #   inferred via an earlier input).
        # * If the input_arg has an explicit type, make sure the input
        #   conforms.

        if _IsListParameter(input_arg):
          if not _IsListValue(values):
            raise TypeError(
                "Expected list for '%s' argument to '%s' Op, not %s." %
                (input_name, op_type_name, values))
          # In cases where we expect all elements of the list to have the
          # same dtype, try to cast non-Tensor elements to that type.
          dtype = None
          if input_arg.type != types_pb2.DT_INVALID:
#.........这里部分代码省略.........