ValueError when Constructing PauliList from Pauli data

[robotastray]

Steps to reproduce the problem

1. Install the qiskit-qec as per instruction
2. Navigate to the repository: cd qiskit-qec
3. Run the test suite: tox -epy311 -- -n ./test/operators/test_pauli_list.py

What is the expected behavior?

The test suite should run without errors, and the test cases should pass successfully.

Actual Behavior:

During the execution of tox -epy311 -- -n ./test/operators/test_pauli_list.py there are several errors of the same type. An error is raised with the following traceback:

DeprecationWarning: Conversion of an array with ndim > 0 to a scalar is deprecated...
...
ValueError: setting an array element with a sequence.

Additional Information:

• The error occurs specifically within the _from_paulis method in the pauli_list.py file.
• The error seems to be related to how the _phase_exp attribute of the Pauli object is being used within the loop.
• It appears that _phase_exp might be an array-like object, and the error is caused when trying to assign its values to the phase_exp NumPy array.
• it is attempting to assign a sequence (e.g. a list or an array) to an individual element within a NumPy array.

Environment:

Python version: 3.11
NumPy version: 1.25.2
qiskit-qec version: latest

[grace-harper]

Thank you!