Barrier

class qiskit.circuit.library.Barrier(num_qubits, label=None)

Bases : Instruction

Barrier instruction.

A barrier is a visual indicator of the grouping of a circuit section. It also acts as a directive for circuit compilation to separate pieces of a circuit so that any optimizations or re-writes are constrained to only act between barriers.

Create new barrier instruction.

Paramètres:

• num_qubits (int) – the number of qubits for the barrier type [Default: 0].

• label (str) – the barrier label

Lève:

TypeError – if barrier label is invalid.

Attributes

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

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(decomposition)

Add a decomposition of the instruction to the SessionEquivalenceLibrary.

assemble()

Assemble a QasmQobjInstruction

broadcast_arguments(qargs, cargs)

Validation of the arguments.

Paramètres:

• qargs (List) – List of quantum bit arguments.

• cargs (List) – List of classical bit arguments.

Yields:

Tuple(List, List) – A tuple with single arguments.

Lève:

CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.

c_if(classical, val)

Set a classical equality condition on this instruction between the register or cbit classical and value val.

Note

This is a setter method, not an additive one. Calling this multiple times will silently override any previously set condition; it does not stack.

copy(name=None)

Copy of the instruction.

Paramètres:

name (str) – name to be given to the copied circuit, if None then the name stays the same.

Renvoie:

a copy of the current instruction, with the name updated if it was provided

Type renvoyé:

qiskit.circuit.Instruction

inverse()

Special case. Return self.

is_parameterized()

Return True .IFF. instruction is parameterized else False

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];).

Obsolète depuis la version 0.25.0: 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(n)

Creates an instruction with gate repeated n amount of times.

Paramètres:

n (int) – Number of times to repeat the instruction

Renvoie:

Containing the definition.

Type renvoyé:

qiskit.circuit.Instruction

Lève:

CircuitError – If n < 1.

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.

Renvoie:

a new instruction with

sub-instructions reversed.

Type renvoyé:

qiskit.circuit.Instruction

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.

Paramètres:

other (instruction) – other instruction.

Renvoie:

are self and other equal up to parameter expressions.

Type renvoyé:

bool

validate_parameter(parameter)

Instruction parameters has no validation or normalization.