Barrier#

class qiskit.circuit.library.Barrier(num_qubits, label=None)[Quellcode]#

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.

Parameter:

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

  • label (str) – the barrier label

Verursacht:

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)[Quellcode]#

Validation of the arguments.

Parameter:

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

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

Yields:

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

Verursacht:

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

c_if(classical, val)[Quellcode]#

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

Bemerkung

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.

Parameter:

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

Rückgabe:

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

Rückgabetyp:

qiskit.circuit.Instruction

inverse()[Quellcode]#

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];).

Veraltet ab 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.

Parameter:

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

Rückgabe:

Containing the definition.

Rückgabetyp:

qiskit.circuit.Instruction

Verursacht:

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.

Rückgabe:

a new instruction with

sub-instructions reversed.

Rückgabetyp:

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.

Parameter:

other (instruction) – other instruction.

Rückgabe:

are self and other equal up to parameter expressions.

Rückgabetyp:

bool

validate_parameter(parameter)#

Instruction parameters has no validation or normalization.