Deprecations¶
All PennyLane deprecations will raise a qml.PennyLaneDeprecationWarning
. Pending and completed
deprecations are listed below.
Pending deprecations¶
The method
Operator.validate_subspace(subspace)
, only employed under a specific set of qutrit operators, has been relocated to theqml.ops.qutrit.parametric_ops
module and will be removed from theOperator
class.Deprecated in v0.35
Will be removed in v0.36
The private functions
_pauli_mult
,_binary_matrix
and_get_pauli_map
from thepauli
module have been deprecated, as they are no longer used anywhere and the same functionality can be achieved using newer features in thepauli
module.Deprecated in v0.35
Will be removed in v0.36
qml.pauli.pauli_mult
andqml.pauli.pauli_mult_with_phase
are now deprecated. Instead, you should useqml.simplify(qml.prod(pauli_1, pauli_2))
to get the reduced operator.>>> op = qml.simplify(qml.prod(qml.PauliX(0), qml.PauliZ(0))) >>> op -1j*(PauliY(wires=[0])) >>> [phase], [base] = op.terms() >>> phase, base (-1j, PauliY(wires=[0]))
Deprecated in v0.35
Will be removed in v0.36
Calling
qml.matrix
without providing awire_order
on objects where the wire order could be ambiguous now raises a warning. This includes tapes with multiple wires, QNodes with a device that does not provide wires, or quantum functions.Deprecated in v0.35
Will raise an error in v0.36
MeasurementProcess.name
andMeasurementProcess.data
have been deprecated, as they contain dummy values that are no longer needed.Deprecated in v0.35
Will be removed in v0.36
The contents of
qml.interfaces
is moved insideqml.workflow
.Contents moved in v0.35
Old import path removed in v0.36
single_tape_transform
,batch_transform
,qfunc_transform
, andop_transform
are deprecated. Instead switch to using the newqml.transform
function. Please refer to the transform docs to see how this can be done.Deprecated in v0.34
Will be removed in v0.36
PauliWord
andPauliSentence
no longer use*
for matrix and tensor products, but instead use@
to conform with the PennyLane convention.Deprecated in v0.35
Will be removed in v0.36
op.ops
andop.coeffs
will be deprecated in the future. Useop.terms()
instead.Added and deprecated for
Sum
andProd
instances in v0.35
Completed deprecation cycles¶
qml.transforms.one_qubit_decomposition
andqml.transforms.two_qubit_decomposition
are removed. Instead, you should useqml.ops.one_qubit_decomposition
andqml.ops.two_qubit_decomposition
.Deprecated in v0.34
Removed in v0.35
Passing additional arguments to a transform that decorates a QNode should now be done through use of
functools.partial
. For example, themetric_tensor()
transform has an optionalapprox
argument which should now be set using:from functools import partial @partial(qml.metric_tensor, approx="block-diag") @qml.qnode(dev) def circuit(weights): ...
The previously-recommended approach is now removed:
@qml.metric_tensor(approx="block-diag") @qml.qnode(dev) def circuit(weights): ...
Alternatively, consider calling the transform directly:
@qml.qnode(dev) def circuit(weights): ... transformed_circuit = qml.metric_tensor(circuit, approx="block-diag")
Deprecated in v0.33
Removed in v0.35
Observable.return_type
has been removed. Instead, you should inspect the type of the surrounding measurement process.Deprecated in v0.34
Removed in v0.35
ClassicalShadow.entropy()
no longer needs anatol
keyword as a better method to estimate entropies from approximate density matrix reconstructions (with potentially negative eigenvalues) has been implemented.Deprecated in v0.34
Removed in v0.35
QuantumScript.is_sampled
andQuantumScript.all_sampled
have been removed. Users should now validate these properties manually.from pennylane.measurements import * sample_types = (SampleMP, CountsMP, ClassicalShadowMP, ShadowExpvalMP) is_sample_type = [isinstance(m, sample_types) for m in tape.measurements] is_sampled = any(is_sample_type) all_sampled = all(is_sample_type)
Deprecated in v0.34
Removed in v0.35
qml.ExpvalCost
has been removed. Users should useqml.expval()
instead.@qml.qnode(dev) def cost_function(params): some_qfunc(params) return qml.expval(Hamiltonian)
Deprecated in v0.24
Removed in v0.35
Specifying
control_values
passed toqml.ctrl
as a string is no longer supported.Deprecated in v0.25
Removed in v0.34
qml.gradients.pulse_generator
has becomeqml.gradients.pulse_odegen
to adhere to paper naming conventions.Deprecated in v0.33
Removed in v0.34
The
prep
keyword argument inQuantumScript
has been removed.StatePrepBase
operations should be placed at the beginning of theops
list instead.Deprecated in v0.33
Removed in v0.34
The public methods of
DefaultQubit
are pending changes to follow the new device API.We will be switching to the new device interface in a coming release. In this new interface, simulation implementation details will be abstracted away from the device class itself and provided by composition, rather than inheritance. Therefore, some public and private methods from
DefaultQubit
will no longer exist, though its behaviour in a workflow will remain the same.If you directly interact with device methods, please consult
pennylane.devices.Device
andpennylane.devices.DefaultQubit
for more information on what the new interface will look like and be prepared to make updates in a coming release. If you have any feedback on these changes, please create an issue or post in our discussion forum.Deprecated in v0.31
Changed in v0.33
The behaviour of
Operator.__eq__
andOperator.__hash__
has been updated. Their documentation has been updated to reflect the incoming changes.The changes to operator equality allow users to use operator equality the same way as with
qml.equal
. With the changes to hashing, unique operators that are equal now have the same hash. These changes now allow behaviour such as the following:>>> qml.RX(0.1, wires=0) == qml.RX(0.1, wires=0) True >>> {qml.PauliZ(0), qml.PauliZ(0)} {PauliZ(wires=[0])}
Meanwhile, the previous behaviour is shown below:
>>> qml.RX(0.1, wires=0) == qml.RX(0.1, wires=0) False >>> {qml.PauliZ(0), qml.PauliZ(0)} {PauliZ(wires=[0]), PauliZ(wires=[0])}
Added in v0.32
Behaviour changed in v0.33
qml.qchem.jordan_wigner
had been removed. Useqml.jordan_wigner
instead. List input to define the fermionic operator is no longer accepted; the fermionic operatorsqml.FermiA
,qml.FermiC
,qml.FermiWord
andqml.FermiSentence
should be used instead. See thepennylane.fermi
module documentation and the Fermionic Operator tutorial for more details.Deprecated in v0.32
Removed in v0.33
The
tuple
input type inqubit_observable
has been removed. Please use a fermionic operator object. Thetuple
return type infermionic_hamiltonian
andfermionic_observable
has been removed and these functions will return a fermionic operator by default.Deprecated in v0.32
Removed in v0.33
The
sampler_seed
argument ofqml.gradients.spsa_grad
has been removed. Instead, thesampler_rng
argument should be set, either to an integer value, which will be used to create a PRNG internally, or to a NumPy pseudo-random number generator (PRNG) created vianp.random.default_rng(seed)
. The advantage of passing a PRNG is that one can reuse that PRNG when callingspsa_grad
multiple times, for instance during an optimization procedure.Deprecated in v0.32
Removed in v0.33
The
RandomLayers.compute_decomposition
keyword argumentratio_imprivitive
has been changed toratio_imprim
to match the call signature of the operation.Deprecated in v0.32
Removed in v0.33
The
QuantumScript.set_parameters
method and theQuantumScript.data
setter have been removed. Please useQuantumScript.bind_new_parameters
instead.Deprecated in v0.32
Removed in v0.33
The
observables
argument inQubitDevice.statistics
is removed. Please usecircuit
instead. Using a list of observables inQubitDevice.statistics
is removed. Please use aQuantumTape
instead.Still accessible in v0.28-v0.31
Removed in v0.32
The CV observables
qml.X
andqml.P
have been removed. Useqml.QuadX
andqml.QuadP
instead.Deprecated in v0.32
Removed in v0.33
The method
tape.unwrap()
and correspondingUnwrapTape
andUnwrap
classes are removed.Deprecated in v0.32
Removed in v0.33
Instead of
tape.unwrap()
, useconvert_to_numpy_parameters()
:from pennylane.transforms import convert_to_numpy_parameters qscript = qml.tape.QuantumTape([qml.RX(torch.tensor(0.1234), 0)], [qml.expval(qml.Hermitian(torch.eye(2), 0))] ) unwrapped_qscript = convert_to_numpy_parameters(qscript) torch_params = qscript.get_parameters() numpy_params = unwrapped_qscript.get_parameters()
qml.enable_return
andqml.disable_return
have been removed. The old return types are no longer available.Deprecated in v0.32
Removed in v0.33
The
mode
keyword argument inQNode
has been removed, as it was only used in the old return system (which has also been removed). Please usegrad_on_execution
instead.Deprecated in v0.32
Removed in v0.33
qml.math.purity
,qml.math.vn_entropy
,qml.math.mutual_info
,qml.math.fidelity
,qml.math.relative_entropy
, andqml.math.max_entropy
no longer support state vectors as input. Please callqml.math.dm_from_state_vector
on the input before passing to any of these functions.Still accepted in v0.31
Removed in v0.32
The
do_queue
keyword argument inqml.operation.Operator
has been removed. This affects all child classes, such asOperation
,Observable
,SymbolicOp
and more. Instead of settingdo_queue=False
, use theqml.QueuingManager.stop_recording()
context.Deprecated in v0.31
Removed in v0.32
The
qml.specs
dictionary longer supports direct key access to certain keys. Instead these quantities can be accessed as fields of the newResources
object saved underspecs_dict["resources"]
:num_operations
is no longer supported, usespecs_dict["resources"].num_gates
num_used_wires
is no longer supported, usespecs_dict["resources"].num_wires
gate_types
is no longer supported, usespecs_dict["resources"].gate_types
gate_sizes
is no longer supported, usespecs_dict["resources"].gate_sizes
depth
is no longer supported, usespecs_dict["resources"].depth
These keys were still accessible in v0.31 and removed in v0.32.
qml.math.reduced_dm
has been removed. Please useqml.math.reduce_dm
orqml.math.reduce_statevector
instead.Still accessible in v0.31
Removed in v0.32
QuantumScript
’sname
keyword argument and property are removed. This also affectsQuantumTape
andOperationRecorder
.Deprecated in v0.31
Removed in v0.32
The
Operation.base_name
property is removed. Please useOperator.name
ortype(obj).__name__
instead.Still accessible in v0.31
Removed in v0.32
LieAlgebraOptimizer
has been renamed. Please useRiemannianGradientOptimizer
instead.Deprecated in v0.31
Removed in v0.32
The
grouping_type
andgrouping_method
arguments ofqchem.molecular_hamiltonian()
are removed.Deprecated in v0.31
Removed in v0.32
Instead, simply construct a new instance of
Hamiltonian
with the grouping specified:H, qubits = molecular_hamiltonian(symbols, coordinates) grouped_h = qml.Hamiltonian( H.coeffs, H.ops, grouping_type=grouping_type, groupingmethod=grouping_method, )
zyz_decomposition
andxyx_decomposition
are removed, useone_qubit_decomposition
with a rotations keyword instead.Deprecated in v0.31
Removed in v0.32
The
qml.utils.sparse_hamiltonian
function has been removed.~.Hamiltonian.sparse_matrix
should be used instead.Deprecated in v0.29
Removed in v0.31
The
collections
module has been removed.Deprecated in v0.29
Removed in v0.31
qml.op_sum
has been removed. Users should useqml.sum
instead.Deprecated in v0.29.
Removed in v0.31.
The argument
argnum
for gradient transforms using the Jax interface is replaced byargnums
.argnum
is automatically changed toargnums
for gradient transforms using JAX and a warning is raised in v0.30argnums
is the only option for gradient transforms using JAX in v0.31
Evolution
now adds a-1
to the input parameter. Beforehand, the minus sign was not included.Transition warning added in v0.29.
Updated to current behaviour in v0.30.
The
seed_recipes
argument inqml.classical_shadow
andqml.shadow_expval
has been removed. An argumentseed
which defaults toNone
can contain an integer with the wanted seed.Still accessible in v0.28, v0.29
Removed in v0.30
The
get_operation
tape method is updated to return the operation index as well, changing its signature.The new signature is available by changing the arg
return_op_index
toTrue
in v0.29The old signature is replaced with the new one in v0.30
The
grouping
module has been removed. The functionality has been moved and reorganized in the newpauli
module underpauli/utils.py
orpauli/grouping/
.Still accessible in v0.27, v0.28, v0.29, v0.30
Removed in v0.31
The functions from
grouping/pauli.py
,grouping/transformations.py
andgrouping/utils.py
have been moved topauli/utils.py
. The remaining functions have been consolidated in thepauli/grouping/
directory.qml.VQECost
is removed.Deprecated in 0.13
Removed in 0.29
In-place inversion —
op.inv()
andop.inverse=value
— is deprecated. Please useqml.adjoint
orqml.pow
instead.Still accessible in v0.27 and v0.28
Removed in v0.29
Don’t use:
>>> v1 = qml.PauliX(0).inv() >>> v2 = qml.PauliX(0) >>> v2.inverse = True
Instead, use:
>>> qml.adjoint(qml.PauliX(0)) Adjoint(PauliX(wires=[0])) >>> qml.pow(qml.PauliX(0), -1) PauliX(wires=[0])**-1 >>> qml.pow(qml.PauliX(0), -1, lazy=False) PauliX(wires=[0]) >>> qml.PauliX(0) ** -1 PauliX(wires=[0])**-1
The
qml.utils.decompose_hamiltonian()
method is removed. Please useqml.pauli_decompose()
.Still accessible in v0.27
Removed in v0.28
qml.tape.get_active_tape
is deprecated. Please useqml.QueuingManager.active_context()
instead.Deprecated in v0.27
Removed in v0.28
qml.transforms.qcut.remap_tape_wires
is deprecated. Please useqml.map_wires
instead.Deprecated in v0.27
Removed in v0.28
QuantumTape.inv()
is deprecated. Please useQuantumTape.adjoint()
instead. This method returns a new tape instead of modifying itself in-place.Deprecated in v0.27
Removed in v0.28
qml.tape.stop_recording
andQuantumTape.stop_recording
are moved toqml.QueuingManager.stop_recording
Deprecated in v0.27
Removed in v0.28
QueuingContext
is renamedQueuingManager
.Deprecated name
QueuingContext
in v0.27Removed in v0.28
QueuingManager.safe_update_info
andAnnotateQueue.safe_update_info
are removed.Deprecated in v0.27
Removed in v0.28
ObservableReturnTypes
Sample
,Variance
,Expectation
,Probability
,State
, andMidMeasure
are moved tomeasurements
fromoperation
.Deprecated in v0.23
Removed in v0.27
The
qml.utils.expand
function is deprecated.qml.math.expand_matrix
should be used instead.Deprecated in v0.24
Removed in v0.27
The
qml.Operation.get_parameter_shift
method is removed. Use the methods of thegradients
module for general parameter-shift rules instead.Deprecated in v0.22
Removed in v0.28
qml.transforms.measurement_grouping
has been removed. Please useqml.transforms.hamiltonian_expand
instead.Deprecated in v0.28
Removed in v0.29
qml.transforms.make_tape
was previously deprecated, but there is no longer a plan to remove it. It no longer raises a warning, and the functionality is unchanged.Deprecated in v0.28
Un-deprecated in v0.29