Python tensorflow.Variables() Examples

def _fisher_vector_product(self, mean_kl: tf.Tensor, var_list: list) -> Callable:
    """Get a function that computes the product of the KL Hessian and some vector v.
    Use the fact that Hv = d^2 L / dt^2 v = d/dt (dL/dt) v = d/dt gv
    Args:
      mean_kl: tf.Tensor. The KL divergence between the old and the new policy
      var_list: list of tf.Variables for which to compute gradients
    Returns:
      lambda, which takes as input a vector v and computes the product Hv
    """

    # Compute the gradients of the KL divergence w.r.t. var_list and flatten them
    grads = tf.gradients(mean_kl, var_list)
    grad  = tf_cg.flatten_tensors(grads)     # shape: [None]

    def compute_hvp(v):
      # Compute the dot product between grad and v
      v     = tf.stop_gradient(v)
      gvp   = tf.reduce_sum(grad * v)
      # Compute the matrix-vector product `Hv`, between the Hessian and v and flatten it
      hvps  = tf.gradients(gvp, var_list)
      hvp   = tf_cg.flatten_tensors(hvps)
      hvp   = tf.check_numerics(hvp, message="Invalid Fisher-vector product")
      return hvp

    return compute_hvp 

def add_prediction_op(self):
        """Adds the core transformation for this model which transforms a batch of input
        data into a batch of predictions. In this case, the transformation is a linear layer plus a
        softmax transformation:

        y = softmax(Wx + b)

        Hint: Make sure to create tf.Variables as needed.
        Hint: For this simple use-case, it's sufficient to initialize both weights W
                    and biases b with zeros.

        Args:
            input_data: A tensor of shape (batch_size, n_features).
        Returns:
            pred: A tensor of shape (batch_size, n_classes)
        """
        ### YOUR CODE HERE
        with tf.variable_scope("transformation"):
            bias = tf.Variable(tf.random_uniform([self.config.n_classes]))
            W = tf.Variable(tf.random_uniform([self.config.n_features, self.config.n_classes]))
            z = tf.matmul(self.input_placeholder, W) + bias
        pred = softmax(z)
        ### END YOUR CODE
        return pred 

def get_tf_params(scope):
    """
    Makes a list of all tf.Variables under this scope

    args
        scope (str)

    returns
        params (list)
    """
    #  find scope parameters
    params = [p for p in tf.trainable_variables()
              if p.name.startswith(scope)]

    #  sort parameters list by the variable name
    return sorted(params, key=lambda var: var.name) 

def var_list(self, mode=VlMode.RAW):
        """
        Get the chunks that define this variable.

        :param mode: (optional, default VL_MODE.RAW) VL_MODE.RAW: returns simply var_list, that may contain tf.Variables
                         or MergedVariables
                     VL_MODE.BASE: returns a list of tf.Variables that are the "base" variables that for this
                     MergedVariable
                     VL_MODE.TENSOR: returns a list of tf.Variables or tf.Tensor from the MergedVariables
        :return: A list that may contain tf.Tensors, tf.Variables and/or MergedVariables
        """
        if mode == VlMode.RAW:
            return self._var_list
        elif mode == VlMode.BASE:
            return self._get_base_variable_list()
        elif mode == VlMode.TENSOR:
            return self._var_list_as_tensors()  # return w unic tensor + copies augmented
        else:
            raise NotImplementedError('mode %d does not exists' % mode) 

def create_session(config_dict=dict(), force_as_default=False):
    config = tf.ConfigProto()
    for key, value in config_dict.items():
        fields = key.split('.')
        obj = config
        for field in fields[:-1]:
            obj = getattr(obj, field)
        setattr(obj, fields[-1], value)
    session = tf.Session(config=config)
    if force_as_default:
        session._default_session = session.as_default()
        session._default_session.enforce_nesting = False
        session._default_session.__enter__()
    return session

#----------------------------------------------------------------------------
# Initialize all tf.Variables that have not already been initialized.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tf.variables_initializer(tf.report_unitialized_variables()).run() 

def init_uninited_vars(vars=None):
    if vars is None: vars = tf.global_variables()
    test_vars = []; test_ops = []
    with tf.control_dependencies(None): # ignore surrounding control_dependencies
        for var in vars:
            assert is_tf_expression(var)
            try:
                tf.get_default_graph().get_tensor_by_name(var.name.replace(':0', '/IsVariableInitialized:0'))
            except KeyError:
                # Op does not exist => variable may be uninitialized.
                test_vars.append(var)
                with absolute_name_scope(var.name.split(':')[0]):
                    test_ops.append(tf.is_variable_initialized(var))
    init_vars = [var for var, inited in zip(test_vars, run(test_ops)) if not inited]
    run([var.initializer for var in init_vars])

#----------------------------------------------------------------------------
# Set the values of given tf.Variables.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tfutil.run([tf.assign(var, value) for var, value in var_to_value_dict.items()] 

def set_vars(var_to_value_dict: dict) -> None:
    """Set the values of given tf.Variables.

    Equivalent to the following, but more efficient and does not bloat the tf graph:
    tflib.run([tf.assign(var, value) for var, value in var_to_value_dict.items()]
    """
    assert_tf_initialized()
    ops = []
    feed_dict = {}

    for var, value in var_to_value_dict.items():
        assert is_tf_expression(var)

        try:
            setter = tf.get_default_graph().get_tensor_by_name(var.name.replace(":0", "/setter:0"))  # look for existing op
        except KeyError:
            with absolute_name_scope(var.name.split(":")[0]):
                with tf.control_dependencies(None):  # ignore surrounding control_dependencies
                    setter = tf.assign(var, tf.placeholder(var.dtype, var.shape, "new_value"), name="setter")  # create new setter

        ops.append(setter)
        feed_dict[setter.op.inputs[1]] = value

    run(ops, feed_dict) 

def create_session(config_dict=dict(), force_as_default=False):
    config = tf.ConfigProto()
    for key, value in config_dict.items():
        fields = key.split('.')
        obj = config
        for field in fields[:-1]:
            obj = getattr(obj, field)
        setattr(obj, fields[-1], value)
    session = tf.Session(config=config)
    if force_as_default:
        session._default_session = session.as_default()
        session._default_session.enforce_nesting = False
        session._default_session.__enter__()
    return session

#----------------------------------------------------------------------------
# Initialize all tf.Variables that have not already been initialized.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tf.variables_initializer(tf.report_unitialized_variables()).run() 

def init_uninited_vars(vars=None):
    if vars is None: vars = tf.global_variables()
    test_vars = []; test_ops = []
    with tf.control_dependencies(None): # ignore surrounding control_dependencies
        for var in vars:
            assert is_tf_expression(var)
            try:
                tf.get_default_graph().get_tensor_by_name(var.name.replace(':0', '/IsVariableInitialized:0'))
            except KeyError:
                # Op does not exist => variable may be uninitialized.
                test_vars.append(var)
                with absolute_name_scope(var.name.split(':')[0]):
                    test_ops.append(tf.is_variable_initialized(var))
    init_vars = [var for var, inited in zip(test_vars, run(test_ops)) if not inited]
    run([var.initializer for var in init_vars])

#----------------------------------------------------------------------------
# Set the values of given tf.Variables.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tfutil.run([tf.assign(var, value) for var, value in var_to_value_dict.items()] 

def init_uninited_vars(vars=None):
    if vars is None: vars = tf.global_variables()
    test_vars = []; test_ops = []
    with tf.control_dependencies(None): # ignore surrounding control_dependencies
        for var in vars:
            assert is_tf_expression(var)
            try:
                tf.get_default_graph().get_tensor_by_name(var.name.replace(':0', '/IsVariableInitialized:0'))
            except KeyError:
                # Op does not exist => variable may be uninitialized.
                test_vars.append(var)
                with absolute_name_scope(var.name.split(':')[0]):
                    test_ops.append(tf.is_variable_initialized(var))
    init_vars = [var for var, inited in zip(test_vars, run(test_ops)) if not inited]
    run([var.initializer for var in init_vars])

#----------------------------------------------------------------------------
# Set the values of given tf.Variables.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tfutil.run([tf.assign(var, value) for var, value in var_to_value_dict.items()] 

def variable_map(self):
    """Map from original variable names into tf.Variables (or lists of them).

    This map translates between variable names relative to the module and the
    corresponding Variable objects that have been created by instantiating it
    in the current graph (with the applicable scoping added). Each key in the
    map is a variable name as created by running the module's defining
    `module_fn` in the root scope of an empty graph. Each value in the map is
    a Variable object, or in case of partitioned variables a list of Variable
    objects.

    This property can be used with `tf.init_from_checkpoint` as `assignment_map`
    in order to restore a pre-trained checkpoint into a Module before calling
    `Module.export()`.

    Returns:
      A dict from the variable names in the Module to the instantiated
      tf.Variables or list of tf.Variables (if partitioned). The keys of this
      map are the same regardless of the scope of where the Module was
      instantiated.
    """
    return self._impl.variable_map 

def assert_no_new_variables():
  """Ensure that no tf.Variables are constructed inside the context.

  Yields:
    None
  Raises:
    ValueError: if there is a variable created.
  """
  num_vars = len(tf.global_variables())
  old_variables = tf.global_variables()
  yield
  if len(tf.global_variables()) != num_vars:
    new_vars = set(tf.global_variables()) - set(old_variables)
    tf.logging.error("NEW VARIABLES CREATED")
    tf.logging.error(10*"=")
    for v in new_vars:
      tf.logging.error(v)

    raise ValueError("Variables created inside an "
                     "assert_no_new_variables context")
  if old_variables != tf.global_variables():
    raise ValueError("Variables somehow changed inside an "
                     "assert_no_new_variables context."
                     "This means something modified the tf.global_variables()") 

def assert_no_new_variables():
  """Ensure that no tf.Variables are constructed inside the context.

  Yields:
    None
  Raises:
    ValueError: if there is a variable created.
  """
  num_vars = len(tf.global_variables())
  old_variables = tf.global_variables()
  yield
  if len(tf.global_variables()) != num_vars:
    new_vars = set(tf.global_variables()) - set(old_variables)
    tf.logging.error("NEW VARIABLES CREATED")
    tf.logging.error(10*"=")
    for v in new_vars:
      tf.logging.error(v)

    raise ValueError("Variables created inside an "
                     "assert_no_new_variables context")
  if old_variables != tf.global_variables():
    raise ValueError("Variables somehow changed inside an "
                     "assert_no_new_variables context."
                     "This means something modified the tf.global_variables()") 

def create_session(config_dict=dict(), force_as_default=False):
    config = tf.ConfigProto()
    for key, value in config_dict.items():
        fields = key.split('.')
        obj = config
        for field in fields[:-1]:
            obj = getattr(obj, field)
        setattr(obj, fields[-1], value)
    session = tf.Session(config=config)
    if force_as_default:
        session._default_session = session.as_default()
        session._default_session.enforce_nesting = False
        session._default_session.__enter__()
    return session

#----------------------------------------------------------------------------
# Initialize all tf.Variables that have not already been initialized.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tf.variables_initializer(tf.report_unitialized_variables()).run() 

def init_uninited_vars(vars=None):
    if vars is None: vars = tf.global_variables()
    test_vars = []; test_ops = []
    with tf.control_dependencies(None): # ignore surrounding control_dependencies
        for var in vars:
            assert is_tf_expression(var)
            try:
                tf.get_default_graph().get_tensor_by_name(var.name.replace(':0', '/IsVariableInitialized:0'))
            except KeyError:
                # Op does not exist => variable may be uninitialized.
                test_vars.append(var)
                with absolute_name_scope(var.name.split(':')[0]):
                    test_ops.append(tf.is_variable_initialized(var))
    init_vars = [var for var, inited in zip(test_vars, run(test_ops)) if not inited]
    run([var.initializer for var in init_vars])

#----------------------------------------------------------------------------
# Set the values of given tf.Variables.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tfutil.run([tf.assign(var, value) for var, value in var_to_value_dict.items()] 

def set_vars(var_to_value_dict: dict) -> None:
    """Set the values of given tf.Variables.

    Equivalent to the following, but more efficient and does not bloat the tf graph:
    tflib.run([tf.assign(var, value) for var, value in var_to_value_dict.items()]
    """
    assert_tf_initialized()
    ops = []
    feed_dict = {}

    for var, value in var_to_value_dict.items():
        assert is_tf_expression(var)

        try:
            setter = tf.get_default_graph().get_tensor_by_name(var.name.replace(":0", "/setter:0"))  # look for existing op
        except KeyError:
            with absolute_name_scope(var.name.split(":")[0]):
                with tf.control_dependencies(None):  # ignore surrounding control_dependencies
                    setter = tf.assign(var, tf.placeholder(var.dtype, var.shape, "new_value"), name="setter")  # create new setter

        ops.append(setter)
        feed_dict[setter.op.inputs[1]] = value

    run(ops, feed_dict) 

def assert_no_new_variables():
  """Ensure that no tf.Variables are constructed inside the context.

  Yields:
    None
  Raises:
    ValueError: if there is a variable created.
  """
  num_vars = len(tf.global_variables())
  old_variables = tf.global_variables()
  yield
  if len(tf.global_variables()) != num_vars:
    new_vars = set(tf.global_variables()) - set(old_variables)
    tf.logging.error("NEW VARIABLES CREATED")
    tf.logging.error(10*"=")
    for v in new_vars:
      tf.logging.error(v)

    raise ValueError("Variables created inside an "
                     "assert_no_new_variables context")
  if old_variables != tf.global_variables():
    raise ValueError("Variables somehow changed inside an "
                     "assert_no_new_variables context."
                     "This means something modified the tf.global_variables()") 

def create_session(config_dict=dict(), force_as_default=False):
    config = tf.ConfigProto()
    for key, value in config_dict.items():
        fields = key.split('.')
        obj = config
        for field in fields[:-1]:
            obj = getattr(obj, field)
        setattr(obj, fields[-1], value)
    session = tf.Session(config=config)
    if force_as_default:
        session._default_session = session.as_default()
        session._default_session.enforce_nesting = False
        session._default_session.__enter__()
    return session

#----------------------------------------------------------------------------
# Initialize all tf.Variables that have not already been initialized.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tf.variables_initializer(tf.report_unitialized_variables()).run() 

def init_uninited_vars(vars=None):
    if vars is None: vars = tf.global_variables()
    test_vars = []; test_ops = []
    with tf.control_dependencies(None): # ignore surrounding control_dependencies
        for var in vars:
            assert is_tf_expression(var)
            try:
                tf.get_default_graph().get_tensor_by_name(var.name.replace(':0', '/IsVariableInitialized:0'))
            except KeyError:
                # Op does not exist => variable may be uninitialized.
                test_vars.append(var)
                with absolute_name_scope(var.name.split(':')[0]):
                    test_ops.append(tf.is_variable_initialized(var))
    init_vars = [var for var, inited in zip(test_vars, run(test_ops)) if not inited]
    run([var.initializer for var in init_vars])

#----------------------------------------------------------------------------
# Set the values of given tf.Variables.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tfutil.run([tf.assign(var, value) for var, value in var_to_value_dict.items()] 

def create_session(config_dict=dict(), force_as_default=False):
    config = tf.ConfigProto(allow_soft_placement=True)
    for key, value in config_dict.items():
        fields = key.split('.')
        obj = config
        for field in fields[:-1]:
            obj = getattr(obj, field)
        setattr(obj, fields[-1], value)
    session = tf.Session(config=config)
    if force_as_default:
        session._default_session = session.as_default()
        session._default_session.enforce_nesting = False
        session._default_session.__enter__()
    return session

#----------------------------------------------------------------------------
# Initialize all tf.Variables that have not already been initialized.
# Equivalent to the following, but more efficient and does not bloat the tf graph:
#   tf.variables_initializer(tf.report_unitialized_variables()).run() 

def set_vars(var_to_value_dict: dict) -> None:
    """Set the values of given tf.Variables.

    Equivalent to the following, but more efficient and does not bloat the tf graph:
    tflib.run([tf.assign(var, value) for var, value in var_to_value_dict.items()]
    """
    assert_tf_initialized()
    ops = []
    feed_dict = {}

    for var, value in var_to_value_dict.items():
        assert is_tf_expression(var)

        try:
            setter = tf.get_default_graph().get_tensor_by_name(var.name.replace(":0", "/setter:0"))  # look for existing op
        except KeyError:
            with absolute_name_scope(var.name.split(":")[0]):
                with tf.control_dependencies(None):  # ignore surrounding control_dependencies
                    setter = tf.assign(var, tf.placeholder(var.dtype, var.shape, "new_value"), name="setter")  # create new setter

        ops.append(setter)
        feed_dict[setter.op.inputs[1]] = value

    run(ops, feed_dict) 

def assert_no_new_variables():
  """Ensure that no tf.Variables are constructed inside the context.

  Yields:
    None
  Raises:
    ValueError: if there is a variable created.
  """
  num_vars = len(tf.global_variables())
  old_variables = tf.global_variables()
  yield
  if len(tf.global_variables()) != num_vars:
    new_vars = set(tf.global_variables()) - set(old_variables)
    tf.logging.error("NEW VARIABLES CREATED")
    tf.logging.error(10*"=")
    for v in new_vars:
      tf.logging.error(v)

    raise ValueError("Variables created inside an "
                     "assert_no_new_variables context")
  if old_variables != tf.global_variables():
    raise ValueError("Variables somehow changed inside an "
                     "assert_no_new_variables context."
                     "This means something modified the tf.global_variables()") 

def add_model(self, input_data):
    """Adds a linear-layer plus a softmax transformation

    The core transformation for this model which transforms a batch of input
    data into a batch of predictions. In this case, the mathematical
    transformation effected is

    y = softmax(xW + b)

    Hint: Make sure to create tf.Variables as needed. Also, make sure to use
          tf.name_scope to ensure that your name spaces are clean.
    Hint: For this simple use-case, it's sufficient to initialize both weights W
          and biases b with zeros.

    Args:
      input_data: A tensor of shape (batch_size, n_features).
    Returns:
      out: A tensor of shape (batch_size, n_classes)
    """
    with tf.variable_scope("softmax_model"):
      self.W = tf.Variable(tf.zeros([self.config.n_features, self.config.n_classes]), name="weights")
      self.b = tf.Variable(tf.zeros([self.config.n_classes]), name="biases")
    return softmax(tf.matmul(input_data, self.W) + self.b) 

def _set_hyper(self, name, value):
    """Set hyper `name` to value. value must be numeric."""
    if self._hypers_created:
      if not isinstance(self._hyper[name], tf.Variable):
        raise AttributeError("Can't set attribute: {}".format(name))
      if not isinstance(value, numbers.Number):
        raise ValueError('Dynamic reassignment only supports setting with a '
                         'number. tf.Tensors and tf.Variables can only be used '
                         'before the internal kfac optimizer is created.')
      backend.set_value(self._hyper[name], value)
    else:
      super(Kfac, self)._set_hyper(name, value) 

def move_to_device(x, device):
    """ Utility function to move a tensor to a device """

    if device is None:
        return x

    # tf.Variables cannot be moved to a device
    if not isinstance(x, tf.Tensor):
        return x

    if isinstance(device, tf.Tensor):
        device = device.device

    # check if device is empty string
    if len(device) == 0:
        return x

    if '/' in device:
        device = device.replace('/', '')

    splits = device.split(':')[-2:]
    device, id = splits
    id = int(id)

    x_device = x.device.lower()

    if 'cpu' in device.lower() and 'cpu' not in x_device:
        x = tf.identity(x)

    elif 'gpu' in device.lower() and 'gpu' not in x_device:
        x = x.gpu(id)

    return x 

def norm_posterior(dim, std0, suffix=None):
    """Initialise a posterior (diagonal) Normal distribution.

    Parameters
    ----------
    dim : tuple or list
        the dimension of this distribution.
    std0 : float, np.array
        the initial (unoptimized) standard deviation of this distribution.
        Must be a scalar or have the same shape as dim.
    suffix : str
        suffix to add to the names of the variables of the parameters of this
        distribution.

    Returns
    -------
    Q : tf.distributions.Normal
        the initialised posterior Normal object.

    Note
    ----
    This will make tf.Variables on the mean standard deviation of the
    posterior. The initialisation of the mean is zero and the initialisation of
    the standard deviation is simply ``std0`` for each element.

    """
    assert (np.ndim(std0) == 0) or (np.shape(std0) == dim)
    mu_0 = tf.zeros(dim)
    mu = tf.Variable(mu_0, name=_add_suffix("W_mu_q", suffix))

    if np.ndim(std0) == 0:
        std0 = tf.ones(dim) * std0

    std = pos_variable(std0, name=_add_suffix("W_std_q", suffix))
    summary_histogram(mu)
    summary_histogram(std)

    Q = tf.distributions.Normal(loc=mu, scale=std)
    return Q 

def init_uninitialized_vars(target_vars: List[tf.Variable] = None) -> None:
    """Initialize all tf.Variables that have not already been initialized.

    Equivalent to the following, but more efficient and does not bloat the tf graph:
    tf.variables_initializer(tf.report_uninitialized_variables()).run()
    """
    assert_tf_initialized()
    if target_vars is None:
        target_vars = tf.global_variables()

    test_vars = []
    test_ops = []

    with tf.control_dependencies(None):  # ignore surrounding control_dependencies
        for var in target_vars:
            assert is_tf_expression(var)

            try:
                tf.get_default_graph().get_tensor_by_name(var.name.replace(":0", "/IsVariableInitialized:0"))
            except KeyError:
                # Op does not exist => variable may be uninitialized.
                test_vars.append(var)

                with absolute_name_scope(var.name.split(":")[0]):
                    test_ops.append(tf.is_variable_initialized(var))

    init_vars = [var for var, inited in zip(test_vars, run(test_ops)) if not inited]
    run([var.initializer for var in init_vars]) 

def init_uninitialized_vars(target_vars: List[tf.Variable] = None) -> None:
    """Initialize all tf.Variables that have not already been initialized.

    Equivalent to the following, but more efficient and does not bloat the tf graph:
    tf.variables_initializer(tf.report_uninitialized_variables()).run()
    """
    assert_tf_initialized()
    if target_vars is None:
        target_vars = tf.global_variables()

    test_vars = []
    test_ops = []

    with tf.control_dependencies(None):  # ignore surrounding control_dependencies
        for var in target_vars:
            assert is_tf_expression(var)

            try:
                tf.get_default_graph().get_tensor_by_name(var.name.replace(":0", "/IsVariableInitialized:0"))
            except KeyError:
                # Op does not exist => variable may be uninitialized.
                test_vars.append(var)

                with absolute_name_scope(var.name.split(":")[0]):
                    test_ops.append(tf.is_variable_initialized(var))

    init_vars = [var for var, inited in zip(test_vars, run(test_ops)) if not inited]
    run([var.initializer for var in init_vars]) 

def count_trainable_parameters():
        """
        Counts the number of trainable parameters (e.g. tf.Variables) to get a rough idea of how complex
        our Model is.

        Returns:
            int: The number of trainable parameters in the graph.
        """
        num_trainable_parameters = 0
        if get_backend() == "tf":
            for variable in tf.trainable_variables():
                num_trainable_parameters += get_shape(variable, flat=True)

        return num_trainable_parameters 

def variables(self):
    """Returns the list of all tf.Variables created by module instantiation."""
    result = []
    for _, value in sorted(self.variable_map.items()):
      if isinstance(value, list):
        result.extend(value)
      else:
        result.append(value)
    return result