Hello! If applicable, put your complete code example down below. Make sure that your code:
- is 100% self-contained — someone can copy-paste exactly what is here and run it to
reproduce the behaviour you are observing - includes comments
n_qubits = 4 # Corresponding to the output dimension of Dense(4)
dev = qml.device("default.qubit", wires=n_qubits)
@qml.qnode(dev, interface="tf")
def quantum_circuit(inputs, weights):
# Encode input data (from the output of Dense(4))
for j in range(n_qubits):
qml.RY(np.pi * inputs[j], wires=j)
# Apply a custom CNOT structure (fixed pattern)
ops = [[1, 2, 3], [2, 3, 0], [3, 0, 1], [0, 1, 2]]
for t in range(4):
control = t
targets = ops[t]
for q in targets:
qml.CNOT(wires=[control, q])
qml.Barrier(wires=range(n_qubits))
# Measure the expectation values of all qubits
return [qml.expval(qml.PauliZ(j)) for j in range(n_qubits)]
weight_shapes = {"weights": (0,)}
qlayer = qml.qnn.KerasLayer(
quantum_circuit,
weight_shapes=weight_shapes,
output_dim=n_qubits
)
If you want help with diagnosing an error, please put the full error message below:
---------------------------------------------------------------------------
ImportError Traceback (most recent call last)
Cell In[12], line 2
1 weight_shapes = {"weights": (0,)}
----> 2 qlayer = qml.qnn.KerasLayer(
3 quantum_circuit,
4 weight_shapes=weight_shapes,
5 output_dim=n_qubits
6 )
File ~\AppData\Roaming\Python\Python39\site-packages\pennylane\qnn\keras.py:321, in KerasLayer.__init__(self, qnode, weight_shapes, output_dim, weight_specs, **kwargs)
313 raise ImportError(
314 "KerasLayer requires TensorFlow version 2 or above. The latest "
315 "version of TensorFlow can be installed using:\n"
316 "pip install tensorflow --upgrade\nAlternatively, visit "
317 "https://www.tensorflow.org/install for detailed instructions."
318 )
320 if not CORRECT_KERAS_VERSION:
--> 321 raise ImportError(
322 "KerasLayer requires a Keras version lower than 3. For instructions on running with Keras 2,"
323 "visit https://keras.io/getting_started/#tensorflow--keras-2-backwards-compatibility."
324 )
326 self.weight_shapes = {
327 weight: (tuple(size) if isinstance(size, Iterable) else (size,) if size > 1 else ())
328 for weight, size in weight_shapes.items()
329 }
331 self._signature_validation(qnode, weight_shapes)
ImportError: KerasLayer requires a Keras version lower than 3. For instructions on running with Keras 2,visit https://keras.io/getting_started/#tensorflow--keras-2-backwards-compatibility.
And, finally, make sure to include the versions of your packages. Specifically, show us the output of qml.about().