BooleanExpression
class qiskit.circuit.classicalfunction.BooleanExpression(expression, name=None, var_order=None)
Bases: ClassicalElement
The Boolean Expression gate.
Parameters
- expression (str) – The logical expression string.
- name (str) – Optional. Instruction gate name. Otherwise part of the expression is going to be used.
- var_order (list) – A list with the order in which variables will be created. (default: by appearance)
Attributes
base_class
Get the base class of this instruction. This is guaranteed to be in the inheritance tree of self.
The “base class” of an instruction is the lowest class in its inheritance tree that the object should be considered entirely compatible with for _all_ circuit applications. This typically means that the subclass is defined purely to offer some sort of programmer convenience over the base class, and the base class is the “true” class for a behavioural perspective. In particular, you should not override base_class if you are defining a custom version of an instruction that will be implemented differently by hardware, such as an alternative measurement strategy, or a version of a parametrised gate with a particular set of parameters for the purposes of distinguishing it in a Target from the full parametrised gate.
This is often exactly equivalent to type(obj), except in the case of singleton instances of standard-library instructions. These singleton instances are special subclasses of their base class, and this property will return that base. For example:
>>> isinstance(XGate(), XGate)
True
>>> type(XGate()) is XGate
False
>>> XGate().base_class is XGate
TrueIn general, you should not rely on the precise class of an instruction; within a given circuit, it is expected that Instruction.name should be a more suitable discriminator in most situations.
condition
The classical condition on the instruction.
condition_bits
Get Clbits in condition.
decompositions
Get the decompositions of the instruction from the SessionEquivalenceLibrary.
definition
Return definition in terms of other basic gates.
duration
Get the duration.
label
Return instruction label
mutable
Is this instance is a mutable unique instance or not.
If this attribute is False the gate instance is a shared singleton and is not mutable.
name
Return the name.
num_clbits
Return the number of clbits.
num_qubits
Return the number of qubits.
params
return instruction params.
unit
Get the time unit of duration.
Methods
add_decomposition
add_decomposition(decomposition)
Add a decomposition of the instruction to the SessionEquivalenceLibrary.
assemble
assemble()
Assemble a QasmQobjInstruction
broadcast_arguments
broadcast_arguments(qargs, cargs)
Validation and handling of the arguments and its relationship.
For example, cx([q[0],q[1]], q[2]) means cx(q[0], q[2]); cx(q[1], q[2]). This method yields the arguments in the right grouping. In the given example:
in: [[q[0],q[1]], q[2]],[]
outs: [q[0], q[2]], []
[q[1], q[2]], []The general broadcasting rules are:
If len(qargs) == 1:
[q[0], q[1]] -> [q[0]],[q[1]]If len(qargs) == 2:
[[q[0], q[1]], [r[0], r[1]]] -> [q[0], r[0]], [q[1], r[1]] [[q[0]], [r[0], r[1]]] -> [q[0], r[0]], [q[0], r[1]] [[q[0], q[1]], [r[0]]] -> [q[0], r[0]], [q[1], r[0]]If len(qargs) >= 3:
[q[0], q[1]], [r[0], r[1]], ...] -> [q[0], r[0], ...], [q[1], r[1], ...]
Parameters
Returns
A tuple with single arguments.
Raises
CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.
Return type
c_if
c_if(classical, val)
Set a classical equality condition on this instruction between the register or cbit classical and value val.
This is a setter method, not an additive one. Calling this multiple times will silently override any previously set condition; it does not stack.
control
control(num_ctrl_qubits=1, label=None, ctrl_state=None)
Return controlled version of gate. See ControlledGate for usage.
Parameters
- num_ctrl_qubits (int) – number of controls to add to gate (default:
1) - label (str | None) – optional gate label
- ctrl_state (int |str | None) – The control state in decimal or as a bitstring (e.g.
'111'). IfNone, use2**num_ctrl_qubits-1.
Returns
Controlled version of gate. This default algorithm uses num_ctrl_qubits-1 ancilla qubits so returns a gate of size num_qubits + 2*num_ctrl_qubits - 1.
Return type
Raises
QiskitError – unrecognized mode or invalid ctrl_state
copy
copy(name=None)
Copy of the instruction.
Parameters
name (str) – name to be given to the copied circuit, if None then the name stays the same.
Returns
a copy of the current instruction, with the name updated if it was provided
Return type
from_dimacs_file
classmethod from_dimacs_file(filename)
Create a BooleanExpression from the string in the DIMACS format. :param filename: A file in DIMACS format.
Returns
A gate for the input string
Return type
Raises
FileNotFoundError – If filename is not found.
inverse
inverse()
Invert this instruction.
If the instruction is composite (i.e. has a definition), then its definition will be recursively inverted.
Special instructions inheriting from Instruction can implement their own inverse (e.g. T and Tdg, Barrier, etc.)
Returns
a fresh instruction for the inverse
Return type
Raises
CircuitError – if the instruction is not composite and an inverse has not been implemented for it.
is_parameterized
is_parameterized()
Return True .IFF. instruction is parameterized else False
power
power(exponent)
Creates a unitary gate as gate^exponent.
Parameters
exponent (float) – Gate^exponent
Returns
To which to_matrix is self.to_matrix^exponent.
Return type
.library.UnitaryGate
Raises
CircuitError – If Gate is not unitary
qasm
qasm()
Return a default OpenQASM string for the instruction.
Derived instructions may override this to print in a different format (e.g. measure q[0] -> c[0];).
The method qiskit.circuit.instruction.Instruction.qasm() is deprecated as of qiskit-terra 0.25.0. It will be removed no earlier than 3 months after the release date. Correct exporting to OpenQASM 2 is the responsibility of a larger exporter; it cannot safely be done on an object-by-object basis without context. No replacement will be provided, because the premise is wrong.
repeat
repeat(n)
Creates an instruction with gate repeated n amount of times.
Parameters
n (int) – Number of times to repeat the instruction
Returns
Containing the definition.
Return type
Raises
CircuitError – If n < 1.
reverse_ops
reverse_ops()
For a composite instruction, reverse the order of sub-instructions.
This is done by recursively reversing all sub-instructions. It does not invert any gate.
Returns
a new instruction with
sub-instructions reversed.
Return type
simulate
simulate(bitstring)
Evaluate the expression on a bitstring.
This evaluation is done classically.
Parameters
bitstring (str) – The bitstring for which to evaluate.
Returns
result of the evaluation.
Return type
soft_compare
soft_compare(other)
Soft comparison between gates. Their names, number of qubits, and classical bit numbers must match. The number of parameters must match. Each parameter is compared. If one is a ParameterExpression then it is not taken into account.
Parameters
other (instruction) – other instruction.
Returns
are self and other equal up to parameter expressions.
Return type
synth
synth(registerless=True, synthesizer=None)
Synthesis the logic network into a QuantumCircuit.
Parameters
- registerless (bool) – Default
True. IfFalseuses the parameter names to create registers with those names. Otherwise, creates a circuit with a flat quantum register. - synthesizer (Callable[[BooleanExpression], QuantumCircuit] | None) – A callable that takes self and returns a Tweedledum circuit.
Returns
A circuit implementing the logic network.
Return type
to_matrix
to_matrix()
Return a Numpy.array for the gate unitary matrix.
Returns
if the Gate subclass has a matrix definition.
Return type
np.ndarray
Raises
CircuitError – If a Gate subclass does not implement this method an exception will be raised when this base class method is called.
to_mutable
to_mutable()
Return a mutable copy of this gate.
This method will return a new mutable copy of this gate instance. If a singleton instance is being used this will be a new unique instance that can be mutated. If the instance is already mutable it will be a deepcopy of that instance.
validate_parameter
validate_parameter(parameter)
Gate parameters should be int, float, or ParameterExpression