qiskit.qpy.dump

dump(circuits, file_obj, metadata_serializer=None)

Write QPY binary data to a file

This function is used to save a circuit to a file for later use or transfer between machines. The QPY format is backwards compatible and can be loaded with future versions of Qiskit.

For example:

from qiskit.circuit import QuantumCircuit
from qiskit.circuit import qpy_serialization
 
qc = QuantumCircuit(2, name='Bell', metadata={'test': True})
qc.h(0)
qc.cx(0, 1)
qc.measure_all()

from this you can write the qpy data to a file:

with open('bell.qpy', 'wb') as fd:
    qpy_serialization.dump(qc, fd)

or a gzip compressed file:

import gzip
 
with gzip.open('bell.qpy.gz', 'wb') as fd:
    qpy_serialization.dump(qc, fd)

Which will save the qpy serialized circuit to the provided file.

Parameters

• circuits (list or QuantumCircuit) – The quantum circuit object(s) to store in the specified file like object. This can either be a single QuantumCircuit object or a list of QuantumCircuits.
• file_obj (file) – The file like object to write the QPY data too
• metadata_serializer (JSONEncoder) – An optional JSONEncoder class that will be passed the QuantumCircuit.metadata dictionary for each circuit in circuits and will be used as the cls kwarg on the json.dump() call to JSON serialize that dictionary.