def check_or_get_class(class_or_name, module_path=None, superclass=None):
"""Returns the class and checks if the class inherits :attr:`superclass`.
Args:
class_or_name: Name or full path to the class, or the class itself.
module_paths (list, optional): Paths to candidate modules to search
for the class. This is used if :attr:`class_or_name` is a string and
the class cannot be located solely based on :attr:`class_or_name`.
The first module in the list that contains the class
is used.
superclass (optional): A (list of) classes that the target class
must inherit.
Returns:
The target class.
Raises:
ValueError: If class is not found based on :attr:`class_or_name` and
:attr:`module_paths`.
TypeError: If class does not inherits :attr:`superclass`.
"""
class_ = class_or_name
if is_str(class_):
class_ = get_class(class_, module_path)
if superclass is not None:
if not issubclass(class_, superclass):
raise TypeError("A subclass of {} is expected. Got: {}".format(
superclass, class_))
return class_
def _recur_join(s):
if len(s) == 0:
return ''
elif is_str(s[0]):
return sep.join(s)
else:
s_ = [_recur_join(si) for si in s]
return _maybe_list_to_array(s_, s)
def _recur_split(s, dtype_as):
"""Splits (possibly nested list of) strings recursively.
"""
if is_str(s):
return _maybe_list_to_array(s.split(), dtype_as)
else:
s_ = [_recur_split(si, dtype_as) for si in s]
return _maybe_list_to_array(s_, s)
def _recur_strip(s):
if is_str(s):
if bos_token == '':
return ' '.join(s.strip().split())
else:
return ' '.join(s.strip().split()).replace(bos_token + ' ', '')
else:
s_ = [_recur_strip(si) for si in s]
return _maybe_list_to_array(s_, s)
def _recur_strip(s):
if is_str(s):
s_tokens = s.split()
if eos_token in s_tokens:
return ' '.join(s_tokens[:s_tokens.index(eos_token)])
else:
return s
else:
s_ = [_recur_strip(si) for si in s]
return _maybe_list_to_array(s_, s)
def check_or_get_instance_with_redundant_kwargs(ins_or_class_or_name,
kwargs,
module_paths=None,
classtype=None):
"""Returns a class instance and checks types.
Only those keyword arguments in :attr:`kwargs` that are included in the
class construction method are used.
Args:
ins_or_class_or_name: Can be of 3 types:
- A class to instantiate.
- A string of the name or module path to a class to \
instantiate.
- The class instance to check types.
kwargs (dict): Keyword arguments for the class constructor.
module_paths (list, optional): Paths to candidate modules to
search for the class. This is used if the class cannot be
located solely based on :attr:`class_name`. The first module
in the list that contains the class is used.
classtype (optional): A (list of) classes of which the instance must
be an instantiation.
Raises:
ValueError: If class is not found based on :attr:`class_name` and
:attr:`module_paths`.
ValueError: If :attr:`kwargs` contains arguments that are invalid
for the class construction.
TypeError: If the instance is not an instantiation of
:attr:`classtype`.
"""
ret = ins_or_class_or_name
if is_str(ret) or isinstance(ret, type):
ret = get_instance_with_redundant_kwargs(ret, kwargs, module_paths)
if classtype is not None:
if not isinstance(ret, classtype):
raise TypeError("An instance of {} is expected. Got: {}".format(
classtype, ret))
return ret
def get_instance(class_or_name, kwargs, module_paths=None):
"""Creates a class instance.
Args:
class_or_name: A class, or its name or full path to a class to
instantiate.
kwargs (dict): Keyword arguments for the class constructor.
module_paths (list, optional): Paths to candidate modules to
search for the class. This is used if the class cannot be
located solely based on :attr:`class_name`. The first module
in the list that contains the class is used.
Returns:
A class instance.
Raises:
ValueError: If class is not found based on :attr:`class_or_name` and
:attr:`module_paths`.
ValueError: If :attr:`kwargs` contains arguments that are invalid
for the class construction.
"""
# Locate the class
class_ = class_or_name
if is_str(class_):
class_ = get_class(class_, module_paths)
# Check validity of arguments
class_args = set(get_args(class_.__init__))
if kwargs is None:
kwargs = {}
for key in kwargs.keys():
if key not in class_args:
raise ValueError(
"Invalid argument for class %s.%s: %s, valid args: %s" %
(class_.__module__, class_.__name__, key, list(class_args)))
return class_(**kwargs)
def get_layer(hparams):
r"""Makes a layer instance.
The layer must be an instance of :tf_main:`tf.layers.Layer <layers/Layer>`.
Args:
hparams (dict or HParams): Hyperparameters of the layer, with
structure:
.. code-block:: python
{
"type": "LayerClass",
"kwargs": {
# Keyword arguments of the layer class
# ...
}
}
Here:
`"type"`: str or layer class or layer instance
The layer type. This can be
- The string name or full module path of a layer class. If
the class name is provided, the class must be in module
:tf_main:`tf.layers <layers>`, :mod:`texar.tf.core`,
or :mod:`texar.tf.custom`.
- A layer class.
- An instance of a layer class.
For example
.. code-block:: python
"type": "Conv1D" # class name
"type": "texar.tf.core.MaxReducePooling1D" # module path
"type": "my_module.MyLayer" # module path
"type": tf.layers.Conv2D # class
"type": Conv1D(filters=10, kernel_size=2) # cell instance
"type": MyLayer(...) # cell instance
`"kwargs"`: dict
A dictionary of keyword arguments for constructor of the
layer class. Ignored if :attr:`"type"` is a layer instance.
- Arguments named "activation" can be a callable,
or a `str` of the name or module path to the activation
function.
- Arguments named "\*_regularizer" and "\*_initializer"
can be a class instance, or a `dict` of hyperparameters of
respective regularizers and initializers. See
- Arguments named "\*_constraint" can be a callable, or a
`str` of the name or full path to the constraint function.
Returns:
A layer instance. If ``hparams["type"]`` is a layer instance, returns it
directly.
Raises:
ValueError: If :attr:`hparams` is `None`.
ValueError: If the resulting layer is not an instance of
:tf_main:`tf.layers.Layer <layers/Layer>`.
"""
if hparams is None:
raise ValueError("`hparams` must not be `None`.")
layer_type = hparams["type"]
if not is_str(layer_type) and not isinstance(layer_type, type):
layer = layer_type
else:
layer_modules = [
"tensorflow.layers", "texar.tf.core", "texar.tf.custom"
]
layer_class = utils.check_or_get_class(layer_type, layer_modules)
if isinstance(hparams, dict):
default_kwargs = _layer_class_to_default_kwargs_map.get(
layer_class, {})
default_hparams = {"type": layer_type, "kwargs": default_kwargs}
hparams = HParams(hparams, default_hparams)
kwargs = {}
for k, v in hparams.kwargs.items():
if k.endswith('_regularizer'):
kwargs[k] = get_regularizer(v)
elif k.endswith('_initializer'):
kwargs[k] = get_initializer(v)
elif k.endswith('activation'):
kwargs[k] = get_activation_fn(v)
elif k.endswith('_constraint'):
kwargs[k] = get_constraint_fn(v)
else:
kwargs[k] = v
layer = utils.get_instance(layer_type, kwargs, layer_modules)
if not isinstance(layer, tf.layers.Layer):
raise ValueError("layer must be an instance of `tf.layers.Layer`.")
return layer
def get_rnn_cell(hparams=None, mode=None):
"""Creates an RNN cell.
See :func:`~texar.tf.core.default_rnn_cell_hparams` for all
hyperparameters and default values.
Args:
hparams (dict or HParams, optional): Cell hyperparameters. Missing
hyperparameters are set to default values.
mode (optional): A Tensor taking value in
:tf_main:`tf.estimator.ModeKeys <estimator/ModeKeys>`, including
`TRAIN`, `EVAL`, and `PREDICT`. If `None`, dropout will be
controlled by :func:`texar.tf.global_mode`.
Returns:
A cell instance.
Raises:
ValueError: If hparams["num_layers"]>1 and hparams["type"] is a class
instance.
ValueError: The cell is not an
:tf_main:`RNNCell <contrib/rnn/RNNCell>` instance.
"""
if hparams is None or isinstance(hparams, dict):
hparams = HParams(hparams, default_rnn_cell_hparams())
d_hp = hparams["dropout"]
if d_hp["variational_recurrent"] and \
len(d_hp["input_size"]) != hparams["num_layers"]:
raise ValueError(
"If variational_recurrent=True, input_size must be a list of "
"num_layers(%d) integers. Got len(input_size)=%d." %
(hparams["num_layers"], len(d_hp["input_size"])))
cells = []
cell_kwargs = hparams["kwargs"].todict()
num_layers = hparams["num_layers"]
for layer_i in range(num_layers):
# Create the basic cell
cell_type = hparams["type"]
if not is_str(cell_type) and not isinstance(cell_type, type):
if num_layers > 1:
raise ValueError(
"If 'num_layers'>1, then 'type' must be a cell class or "
"its name/module path, rather than a cell instance.")
cell_modules = [
'tensorflow.nn.rnn_cell', 'tensorflow.contrib.rnn',
'texar.tf.custom'
]
cell = utils.check_or_get_instance(cell_type, cell_kwargs,
cell_modules, rnn.RNNCell)
# Optionally add dropout
if d_hp["input_keep_prob"] < 1.0 or \
d_hp["output_keep_prob"] < 1.0 or \
d_hp["state_keep_prob"] < 1.0:
vr_kwargs = {}
if d_hp["variational_recurrent"]:
vr_kwargs = {
"variational_recurrent": True,
"input_size": d_hp["input_size"][layer_i],
"dtype": tf.float32
}
input_keep_prob = switch_dropout(d_hp["input_keep_prob"], mode)
output_keep_prob = switch_dropout(d_hp["output_keep_prob"], mode)
state_keep_prob = switch_dropout(d_hp["state_keep_prob"], mode)
cell = rnn.DropoutWrapper(cell=cell,
input_keep_prob=input_keep_prob,
output_keep_prob=output_keep_prob,
state_keep_prob=state_keep_prob,
**vr_kwargs)
# Optionally add residual and highway connections
if layer_i > 0:
if hparams["residual"]:
cell = rnn.ResidualWrapper(cell)
if hparams["highway"]:
cell = rnn.HighwayWrapper(cell)
cells.append(cell)
if hparams["num_layers"] > 1:
cell = rnn.MultiRNNCell(cells)
else:
cell = cells[0]
return cell
def _maybe_name_to_id(self, name_or_id):
if is_str(name_or_id):
if name_or_id not in self._name_to_id:
raise ValueError("Unknown data name: {}".format(name_or_id))
return self._name_to_id[name_or_id]
return name_or_id
def _maybe_str_to_list(list_or_str):
if is_str(list_or_str):
return list_or_str.split()
return list_or_str
