def set_weights(self, weights):
"""Sets the weights of the optimizer, from Numpy arrays.
Should only be called after computing the gradients
(otherwise the optimizer has no weights).
Arguments:
weights: a list of Numpy arrays. The number
of arrays and their shape must match
number of the dimensions of the weights
of the optimizer (i.e. it should match the
output of `get_weights`).
Raises:
ValueError: in case of incompatible weight shapes.
"""
params = self.weights
if len(params) != len(weights):
raise ValueError('Length of the specified weight list (' +
str(len(weights)) +
') does not match the number of weights '
'of the optimizer (' + str(len(params)) + ')')
weight_value_tuples = []
param_values = K.batch_get_value(params)
for pv, p, w in zip(param_values, params, weights):
if pv.shape != w.shape:
raise ValueError('Optimizer weight shape ' + str(pv.shape) +
' not compatible with '
'provided weight shape ' + str(w.shape))
weight_value_tuples.append((p, w))
K.batch_set_value(weight_value_tuples)
def save_weights_to_hdf5_group(f, layers):
from tensorflow.python.keras._impl.keras import __version__ as keras_version # pylint: disable=g-import-not-at-top
save_attributes_to_hdf5_group(
f, 'layer_names', [layer.name.encode('utf8') for layer in layers])
f.attrs['backend'] = K.backend().encode('utf8')
f.attrs['keras_version'] = str(keras_version).encode('utf8')
for layer in layers:
g = f.create_group(layer.name)
symbolic_weights = layer.weights
weight_values = K.batch_get_value(symbolic_weights)
weight_names = []
for i, (w, val) in enumerate(zip(symbolic_weights, weight_values)):
if hasattr(w, 'name') and w.name:
name = str(w.name)
else:
name = 'param_' + str(i)
weight_names.append(name.encode('utf8'))
save_attributes_to_hdf5_group(g, 'weight_names', weight_names)
for name, val in zip(weight_names, weight_values):
param_dset = g.create_dataset(name, val.shape, dtype=val.dtype)
if not val.shape:
# scalar
param_dset[()] = val
else:
param_dset[:] = val
def save_weights_to_hdf5_group(f, layers):
from tensorflow.python.keras._impl.keras import __version__ as keras_version # pylint: disable=g-import-not-at-top
save_attributes_to_hdf5_group(
f, 'layer_names', [layer.name.encode('utf8') for layer in layers])
f.attrs['backend'] = K.backend().encode('utf8')
f.attrs['keras_version'] = str(keras_version).encode('utf8')
for layer in layers:
g = f.create_group(layer.name)
symbolic_weights = layer.weights
weight_values = K.batch_get_value(symbolic_weights)
weight_names = []
for i, (w, val) in enumerate(zip(symbolic_weights, weight_values)):
if hasattr(w, 'name') and w.name:
name = str(w.name)
else:
name = 'param_' + str(i)
weight_names.append(name.encode('utf8'))
save_attributes_to_hdf5_group(g, 'weight_names', weight_names)
for name, val in zip(weight_names, weight_values):
param_dset = g.create_dataset(name, val.shape, dtype=val.dtype)
if not val.shape:
# scalar
param_dset[()] = val
else:
param_dset[:] = val
def get_weights(self):
"""Returns the current value of the weights of the optimizer.
Returns:
A list of numpy arrays.
"""
return K.batch_get_value(self.weights)
def set_weights(self, weights):
"""Sets the weights of the layer, from Numpy arrays.
Arguments:
weights: a list of Numpy arrays. The number
of arrays and their shape must match
number of the dimensions of the weights
of the layer (i.e. it should match the
output of `get_weights`).
Raises:
ValueError: If the provided weights list does not match the
layer's specifications.
"""
params = self.weights
if len(params) != len(weights):
raise ValueError('You called `set_weights(weights)` on layer "' +
self.name + '" with a weight list of length ' +
str(len(weights)) +
', but the layer was expecting ' +
str(len(params)) +
' weights. Provided weights: ' +
str(weights)[:50] + '...')
if not params:
return
weight_value_tuples = []
param_values = K.batch_get_value(params)
for pv, p, w in zip(param_values, params, weights):
if pv.shape != w.shape:
raise ValueError('Layer weight shape ' + str(pv.shape) +
' not compatible with '
'provided weight shape ' + str(w.shape))
weight_value_tuples.append((p, w))
K.batch_set_value(weight_value_tuples)
def set_weights(self, weights):
"""Sets the weights of the layer, from Numpy arrays.
Arguments:
weights: a list of Numpy arrays. The number
of arrays and their shape must match
number of the dimensions of the weights
of the layer (i.e. it should match the
output of `get_weights`).
Raises:
ValueError: If the provided weights list does not match the
layer's specifications.
"""
params = self.weights
if len(params) != len(weights):
raise ValueError('You called `set_weights(weights)` on layer "' +
self.name + '" with a weight list of length ' +
str(len(weights)) + ', but the layer was expecting ' +
str(len(params)) + ' weights. Provided weights: ' +
str(weights)[:50] + '...')
if not params:
return
weight_value_tuples = []
param_values = K.batch_get_value(params)
for pv, p, w in zip(param_values, params, weights):
if pv.shape != w.shape:
raise ValueError('Layer weight shape ' + str(pv.shape) +
' not compatible with '
'provided weight shape ' + str(w.shape))
weight_value_tuples.append((p, w))
K.batch_set_value(weight_value_tuples)
def get_weights(self):
"""Returns the current value of the weights of the optimizer.
Returns:
A list of numpy arrays.
"""
return K.batch_get_value(self.weights)
def set_weights(self, weights):
"""Sets the weights of the optimizer, from Numpy arrays.
Should only be called after computing the gradients
(otherwise the optimizer has no weights).
Arguments:
weights: a list of Numpy arrays. The number
of arrays and their shape must match
number of the dimensions of the weights
of the optimizer (i.e. it should match the
output of `get_weights`).
Raises:
ValueError: in case of incompatible weight shapes.
"""
params = self.weights
if len(params) != len(weights):
raise ValueError(
'Length of the specified weight list (' + str(len(weights)) +
') does not match the number of weights '
'of the optimizer (' + str(len(params)) + ')')
weight_value_tuples = []
param_values = K.batch_get_value(params)
for pv, p, w in zip(param_values, params, weights):
if pv.shape != w.shape:
raise ValueError(
'Optimizer weight shape ' + str(pv.shape) + ' not compatible with '
'provided weight shape ' + str(w.shape))
weight_value_tuples.append((p, w))
K.batch_set_value(weight_value_tuples)
def get_weights(self):
"""Returns the current weights of the layer.
Returns:
Weights values as a list of numpy arrays.
"""
params = self.weights
return K.batch_get_value(params)
def get_weights(self):
"""Returns the current weights of the layer.
Returns:
Weights values as a list of numpy arrays.
"""
params = self.weights
return K.batch_get_value(params)
def save_model(model, filepath, overwrite=True, include_optimizer=True):
"""Saves a model to a HDF5 file.
The saved model contains:
- the model's configuration (topology)
- the model's weights
- the model's optimizer's state (if any)
Thus the saved model can be reinstantiated in
the exact same state, without any of the code
used for model definition or training.
Arguments:
model: Keras model instance to be saved.
filepath: String, path where to save the model.
overwrite: Whether we should overwrite any existing
model at the target location, or instead
ask the user with a manual prompt.
include_optimizer: If True, save optimizer's state together.
Raises:
ImportError: if h5py is not available.
"""
if h5py is None:
raise ImportError('`save_model` requires h5py.')
def get_json_type(obj):
"""Serializes any object to a JSON-serializable structure.
Arguments:
obj: the object to serialize
Returns:
JSON-serializable structure representing `obj`.
Raises:
TypeError: if `obj` cannot be serialized.
"""
# if obj is a serializable Keras class instance
# e.g. optimizer, layer
if hasattr(obj, 'get_config'):
return {'class_name': obj.__class__.__name__, 'config': obj.get_config()}
# if obj is any numpy type
if type(obj).__module__ == np.__name__:
if isinstance(obj, np.ndarray):
return {'type': type(obj), 'value': obj.tolist()}
else:
return obj.item()
# misc functions (e.g. loss function)
if callable(obj):
return obj.__name__
# if obj is a python 'type'
if type(obj).__name__ == type.__name__:
return obj.__name__
raise TypeError('Not JSON Serializable:', obj)
from tensorflow.python.keras._impl.keras import __version__ as keras_version # pylint: disable=g-import-not-at-top
# If file exists and should not be overwritten.
if not overwrite and os.path.isfile(filepath):
proceed = ask_to_proceed_with_overwrite(filepath)
if not proceed:
return
with h5py.File(filepath, mode='w') as f:
f.attrs['keras_version'] = str(keras_version).encode('utf8')
f.attrs['backend'] = K.backend().encode('utf8')
f.attrs['model_config'] = json.dumps(
{
'class_name': model.__class__.__name__,
'config': model.get_config()
},
default=get_json_type).encode('utf8')
model_weights_group = f.create_group('model_weights')
model_layers = model.layers
save_weights_to_hdf5_group(model_weights_group, model_layers)
if include_optimizer and hasattr(model, 'optimizer'):
if isinstance(model.optimizer, optimizers.TFOptimizer):
logging.warning(
'TensorFlow optimizers do not '
'make it possible to access '
'optimizer attributes or optimizer state '
'after instantiation. '
'As a result, we cannot save the optimizer '
'as part of the model save file.'
'You will have to compile your model again after loading it. '
'Prefer using a Keras optimizer instead '
'(see keras.io/optimizers).')
else:
f.attrs['training_config'] = json.dumps(
{
'optimizer_config': {
'class_name': model.optimizer.__class__.__name__,
'config': model.optimizer.get_config()
},
'loss': model.loss,
'metrics': model.metrics,
'sample_weight_mode': model.sample_weight_mode,
'loss_weights': model.loss_weights,
},
default=get_json_type).encode('utf8')
# Save optimizer weights.
symbolic_weights = getattr(model.optimizer, 'weights')
if symbolic_weights:
optimizer_weights_group = f.create_group('optimizer_weights')
weight_values = K.batch_get_value(symbolic_weights)
weight_names = []
for w, val in zip(symbolic_weights, weight_values):
name = str(w.name)
weight_names.append(name.encode('utf8'))
optimizer_weights_group.attrs['weight_names'] = weight_names
for name, val in zip(weight_names, weight_values):
param_dset = optimizer_weights_group.create_dataset(
name, val.shape, dtype=val.dtype)
if not val.shape:
# scalar
param_dset[()] = val
else:
param_dset[:] = val
f.flush()
def save_model(model, filepath, overwrite=True, include_optimizer=True):
"""Saves a model to a HDF5 file.
The saved model contains:
- the model's configuration (topology)
- the model's weights
- the model's optimizer's state (if any)
Thus the saved model can be reinstantiated in
the exact same state, without any of the code
used for model definition or training.
Arguments:
model: Keras model instance to be saved.
filepath: String, path where to save the model.
overwrite: Whether we should overwrite any existing
model at the target location, or instead
ask the user with a manual prompt.
include_optimizer: If True, save optimizer's state together.
Raises:
ImportError: if h5py is not available.
"""
if h5py is None:
raise ImportError('`save_model` requires h5py.')
def get_json_type(obj):
"""Serializes any object to a JSON-serializable structure.
Arguments:
obj: the object to serialize
Returns:
JSON-serializable structure representing `obj`.
Raises:
TypeError: if `obj` cannot be serialized.
"""
# if obj is a serializable Keras class instance
# e.g. optimizer, layer
if hasattr(obj, 'get_config'):
return {
'class_name': obj.__class__.__name__,
'config': obj.get_config()
}
# if obj is any numpy type
if type(obj).__module__ == np.__name__:
if isinstance(obj, np.ndarray):
return {'type': type(obj), 'value': obj.tolist()}
else:
return obj.item()
# misc functions (e.g. loss function)
if callable(obj):
return obj.__name__
# if obj is a python 'type'
if type(obj).__name__ == type.__name__:
return obj.__name__
raise TypeError('Not JSON Serializable:', obj)
from tensorflow.python.keras._impl.keras import __version__ as keras_version # pylint: disable=g-import-not-at-top
# If file exists and should not be overwritten.
if not overwrite and os.path.isfile(filepath):
proceed = ask_to_proceed_with_overwrite(filepath)
if not proceed:
return
with h5py.File(filepath, mode='w') as f:
f.attrs['keras_version'] = str(keras_version).encode('utf8')
f.attrs['backend'] = K.backend().encode('utf8')
f.attrs['model_config'] = json.dumps(
{
'class_name': model.__class__.__name__,
'config': model.get_config()
},
default=get_json_type).encode('utf8')
model_weights_group = f.create_group('model_weights')
model_layers = model.layers
save_weights_to_hdf5_group(model_weights_group, model_layers)
if include_optimizer and hasattr(model, 'optimizer'):
if isinstance(model.optimizer, optimizers.TFOptimizer):
logging.warning(
'TensorFlow optimizers do not '
'make it possible to access '
'optimizer attributes or optimizer state '
'after instantiation. '
'As a result, we cannot save the optimizer '
'as part of the model save file.'
'You will have to compile your model again after loading it. '
'Prefer using a Keras optimizer instead '
'(see keras.io/optimizers).')
else:
f.attrs['training_config'] = json.dumps(
{
'optimizer_config': {
'class_name': model.optimizer.__class__.__name__,
'config': model.optimizer.get_config()
},
'loss': model.loss,
'metrics': model.metrics,
'sample_weight_mode': model.sample_weight_mode,
'loss_weights': model.loss_weights,
},
default=get_json_type).encode('utf8')
# Save optimizer weights.
symbolic_weights = getattr(model.optimizer, 'weights')
if symbolic_weights:
optimizer_weights_group = f.create_group(
'optimizer_weights')
weight_values = K.batch_get_value(symbolic_weights)
weight_names = []
for w, val in zip(symbolic_weights, weight_values):
name = str(w.name)
weight_names.append(name.encode('utf8'))
optimizer_weights_group.attrs[
'weight_names'] = weight_names
for name, val in zip(weight_names, weight_values):
param_dset = optimizer_weights_group.create_dataset(
name, val.shape, dtype=val.dtype)
if not val.shape:
# scalar
param_dset[()] = val
else:
param_dset[:] = val
f.flush()
def save_model(model, filepath, overwrite=True, include_optimizer=True):
"""Saves a model to a HDF5 file.
The saved model contains:
- the model's configuration (topology)
- the model's weights
- the model's optimizer's state (if any)
Thus the saved model can be reinstantiated in
the exact same state, without any of the code
used for model definition or training.
Arguments:
model: Keras model instance to be saved.
filepath: One of the following:
- String, path where to save the model
- `h5py.File` object where to save the model
overwrite: Whether we should overwrite any existing
model at the target location, or instead
ask the user with a manual prompt.
include_optimizer: If True, save optimizer's state together.
Raises:
ImportError: if h5py is not available.
"""
if h5py is None:
raise ImportError('`save_model` requires h5py.')
from tensorflow.python.keras._impl.keras import __version__ as keras_version # pylint: disable=g-import-not-at-top
if not isinstance(filepath, h5py.File):
# If file exists and should not be overwritten.
if not overwrite and os.path.isfile(filepath):
proceed = ask_to_proceed_with_overwrite(filepath)
if not proceed:
return
f = h5py.File(filepath, mode='w')
opened_new_file = True
else:
f = filepath
opened_new_file = False
try:
f.attrs['keras_version'] = str(keras_version).encode('utf8')
f.attrs['backend'] = K.backend().encode('utf8')
f.attrs['model_config'] = json.dumps(
{
'class_name': model.__class__.__name__,
'config': model.get_config()
},
default=serialization.get_json_type).encode('utf8')
model_weights_group = f.create_group('model_weights')
model_layers = model.layers
save_weights_to_hdf5_group(model_weights_group, model_layers)
if include_optimizer and hasattr(model, 'optimizer'):
if isinstance(model.optimizer, optimizers.TFOptimizer):
logging.warning(
'TensorFlow optimizers do not '
'make it possible to access '
'optimizer attributes or optimizer state '
'after instantiation. '
'As a result, we cannot save the optimizer '
'as part of the model save file.'
'You will have to compile your model again after loading it. '
'Prefer using a Keras optimizer instead '
'(see keras.io/optimizers).')
else:
f.attrs['training_config'] = json.dumps(
{
'optimizer_config': {
'class_name': model.optimizer.__class__.__name__,
'config': model.optimizer.get_config()
},
'loss': model.loss,
'metrics': model.metrics,
'sample_weight_mode': model.sample_weight_mode,
'loss_weights': model.loss_weights,
},
default=serialization.get_json_type).encode('utf8')
# Save optimizer weights.
symbolic_weights = getattr(model.optimizer, 'weights')
if symbolic_weights:
optimizer_weights_group = f.create_group('optimizer_weights')
weight_values = K.batch_get_value(symbolic_weights)
weight_names = []
for w, val in zip(symbolic_weights, weight_values):
name = str(w.name)
weight_names.append(name.encode('utf8'))
optimizer_weights_group.attrs['weight_names'] = weight_names
for name, val in zip(weight_names, weight_values):
param_dset = optimizer_weights_group.create_dataset(
name, val.shape, dtype=val.dtype)
if not val.shape:
# scalar
param_dset[()] = val
else:
param_dset[:] = val
f.flush()
finally:
if opened_new_file:
f.close()
