Source code for pennylane.interfaces.set_shots

# Copyright 2018-2021 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.
"""
Contains the set_shots context manager, which allows devices shots
to be temporarily modified.
"""
# pylint: disable=protected-access
import contextlib


[docs]@contextlib.contextmanager def set_shots(device, shots): """Context manager to temporarily change the shots of a device. This context manager can be used in two ways. As a standard context manager: >>> dev = qml.device("default.qubit", wires=2, shots=None) >>> with set_shots(dev, shots=100): ... print(dev.shots) 100 >>> print(dev.shots) None Or as a decorator that acts on a function that uses the device: >>> set_shots(dev, shots=100)(lambda: dev.shots)() 100 """ if shots == device.shots: yield return original_shots = device.shots original_shot_vector = device._shot_vector try: if shots is not False and device.shots != shots: device.shots = shots yield finally: device.shots = original_shots device._shot_vector = original_shot_vector