# Strawberryfields.fock device not loading/working **URL:** \ **Category:** PennyLane Help\ **Created:** [March 14, 2024, 11:35am UTC](https://discuss.pennylane.ai/t/strawberryfields-fock-device-not-loading-working/4280 "2024-03-14T11:35:25Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Rishi](https://avatars.discourse-cdn.com/v4/letter/r/90db22/32.png) [@Rishi](https://discuss.pennylane.ai/u/Rishi)\ **Post date:** [March 14, 2024, 11:35am UTC](https://discuss.pennylane.ai/t/strawberryfields-fock-device-not-loading-working/4280/1 "2024-03-14T11:35:25Z")
Hello! I am trying to code in a displaced fock state kernel and am having trouble simply getting the fock state in strawberryfields.fock to work! Here is my code, ```auto import pennylane as qml import numpy as np dev_gaussian = qml.device("strawberryfields.fock", wires=2, cutoff_dim=10) @qml.qnode(dev_gaussian) def mean_photon_fock(x1, x2,x3,x4, phi): qml.FockState(3,0) qml.FockState(3,1) qml.Displacement(x1, x2, wires=0) qml.Displacement(x3, x4, wires=1) qml.Beamsplitter(np.pi/4, 0, wires=[0, 1]) # qml.Rotation(phi, wires=0) return qml.expval(qml.NumberOperator(0)) print(mean_photon_fock(1,1,-1,-2,0)) print(qml.about()) ``` And my error is as follows: ```auto Traceback (most recent call last): File "c:\Users\Rishi\OneDrive\Documents\Rishi\Uni\2023\Sem 2\PHYS3900\#pennylane test.py", line 38, in dev_gaussian = qml.device("strawberryfields.fock", wires=2, cutoff_dim=10) File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\pennylane\ __init__.py", line 317, in device plugin_device_class = plugin_devices[name].load() File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\pkg_resources\ __init__.py", line 2517, in load return self.resolve() File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\pkg_resources\ __init__.py", line 2523, in resolve module = __import__ (self.module_name, fromlist=[' __name__'], level=0) File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\pennylane_sf\ __init__.py", line 18, in from .fock import StrawberryFieldsFock File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\pennylane_sf\fock.py", line 36, in import strawberryfields as sf File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\strawberryfields\ __init__.py", line 24, in from . import apps File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\strawberryfields\apps\ __init__.py", line 36, in import strawberryfields.apps.qchem File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\strawberryfields\apps\qchem\ __init__.py", line 34, in import strawberryfields.apps.qchem.dynamics File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\strawberryfields\apps\qchem\dynamics.py", line 73, in from strawberryfields.utils import operation File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\strawberryfields\utils\ __init__.py", line 21, in from .program_functions import * File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\strawberryfields\utils\program_functions.py", line 22, in import tensorflow as tf File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\tensorflow\ __init__.py", line 45, in from tensorflow._api.v2 import __internal__ File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\tensorflow\_api\v2\ __internal__ \ __init__.py", line 8, in from tensorflow._api.v2. __internal__ import autograph File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\tensorflow\_api\v2\ __internal__ \autograph\ __init__.py", line 8, in from tensorflow.python.autograph.core.ag_ctx import control_status_ctx # line: 34 File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\tensorflow\python\autograph\core\ag_ctx.py", line 21, in from tensorflow.python.autograph.utils import ag_logging File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\tensorflow\python\autograph\utils\ __init__.py", line 17, in from tensorflow.python.autograph.utils.context_managers import control_dependency_on_returns File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\tensorflow\python\autograph\utils\context_managers.py", line 19, in from tensorflow.python.framework import ops File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\site-packages\tensorflow\python\framework\ops.py", line 5906, in ) -> Optional[Callable[[Any], message.Message]]: File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\typing.py", line 243, in inner return func(*args, **kwds) File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\typing.py", line 316, in __getitem__ return self._getitem(self, parameters) File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\typing.py", line 433, in Optional return Union[arg, type(None)] File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\typing.py", line 243, in inner return func(*args, **kwds) File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\typing.py", line 316, in __getitem__ return self._getitem(self, parameters) File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\typing.py", line 421, in Union parameters = _remove_dups_flatten(parameters) File "C:\Users\Rishi\AppData\Local\Programs\Python\Python39\lib\typing.py", line 215, in _remove_dups_flatten all_params = set(params) TypeError: unhashable type: 'list' ``` Finally, here is the output of `qml.about()`: ```auto Name: PennyLane Version: 0.29.1 Summary: PennyLane is a Python quantum machine learning library by Xanadu Inc. Home-page: https://github.com/XanaduAI/pennylane Author: Author-email: License: Apache License 2.0 Location: c:\users\rishi\appdata\local\programs\python\python39\lib\site-packages Requires: appdirs, autograd, autoray, cachetools, networkx, numpy, pennylane-lightning, requests, retworkx, scipy, semantic-version, toml Required-by: PennyLane-Lightning, PennyLane-SF Platform info: Windows-10-10.0.22621-SP0 Python version: 3.9.0 Numpy version: 1.23.5 Scipy version: 1.10.1 Installed devices: - default.gaussian (PennyLane-0.29.1) - default.mixed (PennyLane-0.29.1) - default.qubit (PennyLane-0.29.1) - default.qubit.autograd (PennyLane-0.29.1) - default.qubit.jax (PennyLane-0.29.1) - default.qubit.tf (PennyLane-0.29.1) - default.qubit.torch (PennyLane-0.29.1) - default.qutrit (PennyLane-0.29.1) - null.qubit (PennyLane-0.29.1) - lightning.qubit (PennyLane-Lightning-0.30.0) - strawberryfields.fock (PennyLane-SF-0.29.1) - strawberryfields.gaussian (PennyLane-SF-0.29.1) - strawberryfields.gbs (PennyLane-SF-0.29.1) - strawberryfields.remote (PennyLane-SF-0.29.1) - strawberryfields.tf (PennyLane-SF-0.29.1) None ``` ---
**Author:** ![isaacdevlugt](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/isaacdevlugt/32/1159_2.png) [@isaacdevlugt](https://discuss.pennylane.ai/u/isaacdevlugt)\ **Post date:** [March 14, 2024, 8:53pm UTC](https://discuss.pennylane.ai/t/strawberryfields-fock-device-not-loading-working/4280/2 "2024-03-14T20:53:50Z")
Hey @Rishi, welcome to the forum! Interesting… I can’t replicate the issue you’re having 🤔. Here’s my qml.about(): ```auto Name: PennyLane Version: 0.29.1 Summary: PennyLane is a Python quantum machine learning library by Xanadu Inc. Home-page: https://github.com/XanaduAI/pennylane Author: Author-email: License: Apache License 2.0 Location: /Users/isaac/.virtualenvs/pennylane-strawberryfields/lib/python3.11/site-packages Requires: appdirs, autograd, autoray, cachetools, networkx, numpy, pennylane-lightning, requests, retworkx, scipy, semantic-version, toml Required-by: PennyLane-Lightning, PennyLane-SF Platform info: macOS-14.4-arm64-arm-64bit Python version: 3.11.6 Numpy version: 1.23.5 Scipy version: 1.12.0 Installed devices: - default.gaussian (PennyLane-0.29.1) - default.mixed (PennyLane-0.29.1) - default.qubit (PennyLane-0.29.1) - default.qubit.autograd (PennyLane-0.29.1) - default.qubit.jax (PennyLane-0.29.1) - default.qubit.tf (PennyLane-0.29.1) - default.qubit.torch (PennyLane-0.29.1) - default.qutrit (PennyLane-0.29.1) - null.qubit (PennyLane-0.29.1) - lightning.qubit (PennyLane-Lightning-0.30.0) - strawberryfields.fock (PennyLane-SF-0.29.1) - strawberryfields.gaussian (PennyLane-SF-0.29.1) - strawberryfields.gbs (PennyLane-SF-0.29.1) - strawberryfields.remote (PennyLane-SF-0.29.1) - strawberryfields.tf (PennyLane-SF-0.29.1) ``` I’m using python 3.11, but that shouldn’t matter. What I recommend here is to create a fresh virtual environment, install the right packages in that environment, and make sure you use that environment when you run your code! Let me know if that helps 🙂 ---
**Author:** ![Rishi](https://avatars.discourse-cdn.com/v4/letter/r/90db22/32.png) [@Rishi](https://discuss.pennylane.ai/u/Rishi)\ **Post date:** [March 18, 2024, 11:53pm UTC](https://discuss.pennylane.ai/t/strawberryfields-fock-device-not-loading-working/4280/3 "2024-03-18T23:53:19Z")
Perfect thanks so much that works perfectly in a new environment! ---
**Author:** ![isaacdevlugt](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/isaacdevlugt/32/1159_2.png) [@isaacdevlugt](https://discuss.pennylane.ai/u/isaacdevlugt)\ **Post date:** [March 19, 2024, 10:55pm UTC](https://discuss.pennylane.ai/t/strawberryfields-fock-device-not-loading-working/4280/4 "2024-03-19T22:55:26Z")
Awesome! Glad I could help 🙂