Source code for pennylane.io

# Copyright 2020 Xanadu Quantum Technologies Inc.

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
This module contains functions to load circuits from other frameworks as
PennyLane templates.
"""
from pkg_resources import iter_entry_points

# get list of installed plugin converters
plugin_converters = {entry.name: entry for entry in iter_entry_points("pennylane.io")}


[docs]def load(quantum_circuit_object, format: str): """Load external quantum assembly and quantum circuits from supported frameworks into PennyLane templates. .. note:: For more details on which formats are supported please consult the corresponding plugin documentation: https://pennylane.ai/plugins.html **Example:** >>> qc = qiskit.QuantumCircuit(2) >>> qc.rz(0.543, [0]) >>> qc.cx(0, 1) >>> my_circuit = qml.load(qc, format='qiskit') The ``my_circuit`` template can now be used within QNodes, as a two-wire quantum template. >>> @qml.qnode(dev) >>> def circuit(x): >>> qml.RX(x, wires=1) >>> my_circuit(wires=(1, 0)) >>> return qml.expval(qml.PauliZ(0)) Args: quantum_circuit_object: the quantum circuit that will be converted to a PennyLane template format (str): the format of the quantum circuit object to convert from Returns: function: the PennyLane template created from the quantum circuit object """ if format in plugin_converters: # loads the plugin load function plugin_converter = plugin_converters[format].load() # calls the load function of the converter on the quantum circuit object return plugin_converter(quantum_circuit_object) raise ValueError( "Converter does not exist. Make sure the required plugin is installed " "and supports conversion." )
[docs]def from_qiskit(quantum_circuit): """Loads Qiskit QuantumCircuit objects by using the converter in the PennyLane-Qiskit plugin. **Example:** >>> qc = qiskit.QuantumCircuit(2) >>> qc.rz(0.543, [0]) >>> qc.cx(0, 1) >>> my_circuit = qml.from_qiskit(qc) The ``my_circuit`` template can now be used within QNodes, as a two-wire quantum template. >>> @qml.qnode(dev) >>> def circuit(x): >>> qml.RX(x, wires=1) >>> my_circuit(wires=(1, 0)) >>> return qml.expval(qml.PauliZ(0)) Args: quantum_circuit (qiskit.QuantumCircuit): a quantum circuit created in qiskit Returns: function: the PennyLane template created based on the QuantumCircuit object """ return load(quantum_circuit, format="qiskit")
[docs]def from_qasm(quantum_circuit: str): """Loads quantum circuits from a QASM string using the converter in the PennyLane-Qiskit plugin. **Example:** .. code-block:: python >>> hadamard_qasm = 'OPENQASM 2.0;' \\ ... 'include "qelib1.inc";' \\ ... 'qreg q[1];' \\ ... 'h q[0];' >>> my_circuit = qml.from_qasm(hadamard_qasm) The ``my_circuit`` template can now be used within QNodes, as a two-wire quantum template. >>> @qml.qnode(dev) >>> def circuit(x): >>> qml.RX(x, wires=1) >>> my_circuit(wires=(1, 0)) >>> return qml.expval(qml.PauliZ(0)) Args: quantum_circuit (str): a QASM string containing a valid quantum circuit Returns: function: the PennyLane template created based on the QASM string """ return load(quantum_circuit, format="qasm")
[docs]def from_qasm_file(qasm_filename: str): """Loads quantum circuits from a QASM file using the converter in the PennyLane-Qiskit plugin. **Example:** >>> my_circuit = qml.from_qasm("hadamard_circuit.qasm") The ``my_circuit`` template can now be used within QNodes, as a two-wire quantum template. >>> @qml.qnode(dev) >>> def circuit(x): >>> qml.RX(x, wires=1) >>> my_circuit(wires=(1, 0)) >>> return qml.expval(qml.PauliZ(0)) Args: qasm_filename (str): path to a QASM file containing a valid quantum circuit Returns: function: the PennyLane template created based on the QASM file """ return load(qasm_filename, format="qasm_file")
[docs]def from_pyquil(pyquil_program): """Loads pyQuil Program objects by using the converter in the PennyLane-Forest plugin. **Example:** >>> program = pyquil.Program() >>> program += pyquil.gates.H(0) >>> program += pyquil.gates.CNOT(0, 1) >>> my_circuit = qml.from_pyquil(program) The ``my_circuit`` template can now be used within QNodes, as a two-wire quantum template. >>> @qml.qnode(dev) >>> def circuit(x): >>> qml.RX(x, wires=1) >>> my_circuit(wires=[1, 0]) >>> return qml.expval(qml.PauliZ(0)) Args: pyquil_program (pyquil.Program): a program created in pyQuil Returns: pennylane_forest.ProgramLoader: a ``pennylane_forest.ProgramLoader`` instance that can be used like a PennyLane template and that contains additional inspection properties """ return load(pyquil_program, format="pyquil_program")
[docs]def from_quil(quil: str): """Loads quantum circuits from a Quil string using the converter in the PennyLane-Forest plugin. **Example:** .. code-block:: python >>> quil_str = 'H 0\\n' ... 'CNOT 0 1' >>> my_circuit = qml.from_quil(quil_str) The ``my_circuit`` template can now be used within QNodes, as a two-wire quantum template. >>> @qml.qnode(dev) >>> def circuit(x): >>> qml.RX(x, wires=1) >>> my_circuit(wires=(1, 0)) >>> return qml.expval(qml.PauliZ(0)) Args: quil (str): a Quil string containing a valid quantum circuit Returns: pennylane_forest.ProgramLoader: a ``pennylane_forest.ProgramLoader`` instance that can be used like a PennyLane template and that contains additional inspection properties """ return load(quil, format="quil")
[docs]def from_quil_file(quil_filename: str): """Loads quantum circuits from a Quil file using the converter in the PennyLane-Forest plugin. **Example:** >>> my_circuit = qml.from_quil_file("teleportation.quil") The ``my_circuit`` template can now be used within QNodes, as a two-wire quantum template. >>> @qml.qnode(dev) >>> def circuit(x): >>> qml.RX(x, wires=1) >>> my_circuit(wires=(1, 0)) >>> return qml.expval(qml.PauliZ(0)) Args: quil_filename (str): path to a Quil file containing a valid quantum circuit Returns: pennylane_forest.ProgramLoader: a ``pennylane_forest.ProgramLoader`` instance that can be used like a PennyLane template and that contains additional inspection properties """ return load(quil_filename, format="quil_file")