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Clbit

class qiskit.circuit.Clbit(register=None, index=None)

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Bases: Bit

Implement a classical bit.

Creates a classical bit.

Parameters

  • register (ClassicalRegister) – Optional. A classical register containing the bit.
  • index (int) – Optional. The index of the bit in its containing register.

Raises

CircuitError – if the provided register is not a valid ClassicalRegister


Attributes

index

Get the index of an old-style bit in the register that owns it.

In modern Qiskit Terra (version 0.17+), bits are the fundamental object and registers are aliases to collections of bits. A bit can be in many registers depending on the circuit, so a single containing register is no longer a property of a bit. It is an error to access this attribute on bits that were not constructed as “owned” by a register.

Deprecated since version 0.17

The property qiskit.circuit.bit.Bit.index is deprecated as of qiskit-terra 0.17. It will be removed in the Qiskit 1.0 release. Instead, use find_bit() to find all the containing registers within a circuit and the index of the bit within the circuit.

register

Get the register of an old-style bit.

In modern Qiskit Terra (version 0.17+), bits are the fundamental object and registers are aliases to collections of bits. A bit can be in many registers depending on the circuit, so a single containing register is no longer a property of a bit. It is an error to access this attribute on bits that were not constructed as “owned” by a register.

Deprecated since version 0.17

The property qiskit.circuit.bit.Bit.register is deprecated as of qiskit-terra 0.17. It will be removed in the Qiskit 1.0 release. Instead, use find_bit() to find all the containing registers within a circuit and the index of the bit within the circuit.

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