Ruff format

.github/workflows/build-test-actions.yml

@@ -39,7 +39,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install poetry
           poetry install --no-interaction
-      - name: Code Analyzer Checks
+      - name: Additional linter/formatter checks
         run: |
           poetry run pylint --fail-under=10.0 toqito/
 

docs/conf.py

@@ -43,19 +43,19 @@
     "sphinx.ext.githubpages",
     "sphinx.ext.napoleon",
     "sphinxcontrib.bibtex",
-    "sphinx_wagtail_theme"
+    "sphinx_wagtail_theme",
 ]
 
 bibtex_bibfiles = ["books.bib", "articles.bib"]
 bibtex_default_style = "unsrt"
 suppress_warnings = ["bibtex.duplicate_label", "bibtex.duplicate_citation"]
 # we need to skip these warnigns because all the references appear twice, in a function docstring
-# and on the references page. 
+# and on the references page.
 master_doc = "index"
 # autosummary_generate = True
 # autodoc_typehints = "none"
-autoapi_dirs = ['../toqito']
-autoapi_type = 'python'
+autoapi_dirs = ["../toqito"]
+autoapi_type = "python"
 autoapi_ignore = [
     "*/channel_metrics/tests/*",
     "*/rand/tests/*",
@@ -74,8 +74,9 @@
     "*/states/tests/*",
     "*/channel_props/tests/*",
     "*/measurement_ops/tests/*",
-    "*/measurement_props/tests/*"]
-autodoc_typehints = 'description'
+    "*/measurement_props/tests/*",
+]
+autodoc_typehints = "description"
 autoapi_add_toctree_entry = False
 autoapi_keep_files = False
 
@@ -94,7 +95,7 @@
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 
-html_theme = 'sphinx_wagtail_theme'
+html_theme = "sphinx_wagtail_theme"
 html_logo = "figures/logo.svg"
 html_favicon = "figures/favicon.ico"
 
@@ -106,9 +107,7 @@
 
 # This github_url will point to the appropriate page in the default branch.
 # Ex: Getting Started -> https://github.com/vprusso/toqito/blob/master/docs/getting_started.rst
-html_theme_options = dict(
-    github_url = "https://github.com/vprusso/toqito/blob/master/docs/"
-)
+html_theme_options = dict(github_url="https://github.com/vprusso/toqito/blob/master/docs/")
 
 # Show in footer when the docs were last updated.
 html_last_updated_fmt = "%b %d, %Y"

pyproject.toml

@@ -87,7 +87,6 @@ ignore = ["D407", "D203", "D213", "D416", "PLR0912", "PLR0911", "PLR0915", "PLR2
 # PLR0915 -- Checks for functions or methods with too many statements. The default number is 50. 
 # PLR2004 -- Checks if an equality or an inequality is compared to a variable or a num (prefers variable pre)
 # PLR0913 Too many arguments in function definition
-
 [tool.ruff.lint.per-file-ignores]
 "__init__.py" = ["I001"]
 # I001 - skip checking Import block is un-sorted or un-formatted

setup.py

@@ -15,7 +15,7 @@
     "pytest",
     "pytest-cov",
     "qiskit",
-    "scs"
+    "scs",
 ]
 
 setuptools.setup(

toqito/channel_metrics/__init__.py

@@ -1,4 +1,5 @@
 """Distance metrics for quantum channels."""
+
 from toqito.channel_metrics.channel_fidelity import channel_fidelity
 from toqito.channel_metrics.diamond_norm import diamond_norm
 from toqito.channel_metrics.fidelity_of_separability import fidelity_of_separability

toqito/channel_metrics/channel_fidelity.py

@@ -1,4 +1,5 @@
 """Compute the channel fidelity between two quantum channels."""
+
 import cvxpy
 import numpy as np
 

toqito/channel_metrics/completely_bounded_spectral_norm.py

@@ -1,4 +1,5 @@
 """Compute the completely bounded spectral norm of a quantum channel."""
+
 import numpy as np
 
 from toqito.channel_metrics import completely_bounded_trace_norm

toqito/channel_metrics/completely_bounded_trace_norm.py

@@ -1,4 +1,5 @@
 """Compute the completely bounded trace norm of a quantum channel."""
+
 import cvxpy as cp
 import numpy as np
 
@@ -41,9 +42,7 @@ def completely_bounded_trace_norm(phi: np.ndarray) -> float:
     dim_lx, dim_ly = phi.shape
 
     if dim_lx != dim_ly:
-        raise ValueError(
-            "The input and output spaces of the superoperator phi must both be square."
-        )
+        raise ValueError("The input and output spaces of the superoperator phi must both be square.")
 
     if is_quantum_channel(phi):
         return 1
@@ -65,8 +64,7 @@ def completely_bounded_trace_norm(phi: np.ndarray) -> float:
     a_var = cp.bmat([[y0, -phi], [-phi.conj().T, y1]])
     constraints += [a_var >> 0]
     objective = cp.Minimize(
-        cp.norm(cp.partial_trace(y0, dims=(dim, dim), axis=1))
-        + cp.norm(cp.partial_trace(y1, dims=(dim, dim), axis=1))
+        cp.norm(cp.partial_trace(y0, dims=(dim, dim), axis=1)) + cp.norm(cp.partial_trace(y1, dims=(dim, dim), axis=1))
     )
 
     problem = cp.Problem(objective, constraints)

toqito/channel_metrics/diamond_norm.py

@@ -1,4 +1,5 @@
 """Compute the diamond norm between two quantum channels."""
+
 import cvxpy
 import numpy as np
 

toqito/channel_metrics/fidelity_of_separability.py

@@ -146,7 +146,7 @@ def fidelity_of_separability(
 
     # List of extenstion systems and dimension of the Choi matrix.
     sys_ext = list(range(2, 2 + k - 1))
-    dim_choi = dim_r * (dim_a ** k)
+    dim_choi = dim_r * (dim_a**k)
 
     # Projection onto symmetric subspace on AA'.
     pi_sym = symmetric_projection(dim_a, 2)
@@ -163,19 +163,15 @@ def fidelity_of_separability(
                 pi_sym
                 * picos.partial_trace(
                     (picos.partial_transpose(psi, [0], psi_dims) @ picos.I(dim_a))
-                    * permute_systems(
-                        choi_partial @ picos.I(dim_b * dim_a), [1, 4, 3, 2], dim_list
-                    ),
+                    * permute_systems(choi_partial @ picos.I(dim_b * dim_a), [1, 4, 3, 2], dim_list),
                     [0, 2],
                     dim_list,
                 )
             )
         ),
     )
 
-    problem.add_constraint(
-        picos.partial_trace(choi, list(range(1, k + 1)), choi_dims) == picos.I(dim_r)
-    )
+    problem.add_constraint(picos.partial_trace(choi, list(range(1, k + 1)), choi_dims) == picos.I(dim_r))
     problem.add_constraint(choi >> 0)
 
     # k-extendablility of Choi state

toqito/channel_metrics/tests/test_channel_fidelity.py

@@ -1,4 +1,5 @@
 """Tests for channel_fidelity."""
+
 import numpy as np
 import pytest
 
@@ -8,24 +9,36 @@
 dephasing_channel = dephasing(4)
 depolarizing_channel = depolarizing(4)
 
-@pytest.mark.parametrize("input1, input2, expected_value", [
-    # fidelity of identical channels
-    (dephasing_channel, dephasing_channel, 1),
-    # fidelity of different channels
-    (dephasing_channel, depolarizing_channel, 1/2)])
+
+@pytest.mark.parametrize(
+    "input1, input2, expected_value",
+    [
+        # fidelity of identical channels
+        (dephasing_channel, dephasing_channel, 1),
+        # fidelity of different channels
+        (dephasing_channel, depolarizing_channel, 1 / 2),
+    ],
+)
 def test_channel_fidelity(input1, input2, expected_value):
     """Test functions works as expected for valid inputs."""
     calculated_value = channel_fidelity(input1, input2)
     assert pytest.approx(expected_value, 1e-3) == calculated_value
 
 
-@pytest.mark.parametrize("input1, input2, expected_msg", [
-    # Inconsistent dimensions between Choi matrices
-    (depolarizing_channel, depolarizing(2), "The Choi matrices provided should be of equal dimension."),
-    # Non-square inputs for channel fidelity
-    (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1, 2, 3], [4, 5, 6]]), "The Choi matrix provided must be square.")])
+@pytest.mark.parametrize(
+    "input1, input2, expected_msg",
+    [
+        # Inconsistent dimensions between Choi matrices
+        (depolarizing_channel, depolarizing(2), "The Choi matrices provided should be of equal dimension."),
+        # Non-square inputs for channel fidelity
+        (
+            np.array([[1, 2, 3], [4, 5, 6]]),
+            np.array([[1, 2, 3], [4, 5, 6]]),
+            "The Choi matrix provided must be square.",
+        ),
+    ],
+)
 def test_channel_fidelity_raises_error(input1, input2, expected_msg):
     """Test functions works as expected for valid inputs."""
-    with pytest.raises(ValueError, match = expected_msg):
+    with pytest.raises(ValueError, match=expected_msg):
         channel_fidelity(input1, input2)
-

toqito/channel_metrics/tests/test_completely_bounded_spectral_norm.py

@@ -1,6 +1,5 @@
 """Tests for completely_bounded_spectral_norm."""
 
-
 from toqito.channel_metrics import (
     completely_bounded_spectral_norm,
     completely_bounded_trace_norm,

toqito/channel_metrics/tests/test_completely_bounded_trace_norm.py

@@ -1,4 +1,5 @@
 """Tests for completely_bounded_trace_norm."""
+
 import numpy as np
 import pytest
 
@@ -14,13 +15,17 @@
 diameter = np.max(dist)
 
 
-@pytest.mark.parametrize("test_input, expected", [
-    # The diamond norm of a quantum channel is 1
-    (dephasing(2), 1),
-    # the diamond norm of a CP map
-    (np.eye(4), 4.0),
-    # unitaries channel, phi, diameter in terms of the eigenvalues of U
-    (phi, diameter)])
+@pytest.mark.parametrize(
+    "test_input, expected",
+    [
+        # The diamond norm of a quantum channel is 1
+        (dephasing(2), 1),
+        # the diamond norm of a CP map
+        (np.eye(4), 4.0),
+        # unitaries channel, phi, diameter in terms of the eigenvalues of U
+        (phi, diameter),
+    ],
+)
 def test_cb_trace_norm(test_input, expected):
     """Test function works as expected for valid inputs."""
     calculated_value = completely_bounded_trace_norm(test_input)

toqito/channel_metrics/tests/test_diamond_norm.py

@@ -1,29 +1,41 @@
 """Tests for diamond_norm."""
+
 import numpy as np
 import pytest
 
 from toqito.channel_metrics import diamond_norm
 from toqito.channels import dephasing, depolarizing
 
 
-@pytest.mark.parametrize("test_input1, test_input_2, expected", [
-    # The diamond norm of identical channels should yield 0
-    (dephasing(2), dephasing(2), 0),
-    # the diamond norm of different channels
-    (dephasing(2), depolarizing(2), 1)])
+@pytest.mark.parametrize(
+    "test_input1, test_input_2, expected",
+    [
+        # The diamond norm of identical channels should yield 0
+        (dephasing(2), dephasing(2), 0),
+        # the diamond norm of different channels
+        (dephasing(2), depolarizing(2), 1),
+    ],
+)
 def test_diamond_norm_valid_inputs(test_input1, test_input_2, expected):
     """Test function works as expected for valid inputs."""
     calculated_value = diamond_norm(test_input1, test_input_2)
     assert pytest.approx(expected, 1e-3) == calculated_value
 
 
-@pytest.mark.parametrize("test_input1, test_input_2, expected_msg", [
-    # Inconsistent dimensions between Choi matrices
-    (depolarizing(4), dephasing(2), "The Choi matrices provided should be of equal dimension."),
-    # Non-square inputs for diamond norm
-    (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1, 2, 3], [4, 5, 6]]), "The Choi matrix provided must be square.")])
+@pytest.mark.parametrize(
+    "test_input1, test_input_2, expected_msg",
+    [
+        # Inconsistent dimensions between Choi matrices
+        (depolarizing(4), dephasing(2), "The Choi matrices provided should be of equal dimension."),
+        # Non-square inputs for diamond norm
+        (
+            np.array([[1, 2, 3], [4, 5, 6]]),
+            np.array([[1, 2, 3], [4, 5, 6]]),
+            "The Choi matrix provided must be square.",
+        ),
+    ],
+)
 def test_diamond_norm_invalid_inputs(test_input1, test_input_2, expected_msg):
     """Test function raises error as expected for invalid inputs."""
-    with pytest.raises(ValueError, match = expected_msg):
+    with pytest.raises(ValueError, match=expected_msg):
         diamond_norm(test_input1, test_input_2)
-

toqito/channel_metrics/tests/test_fidelity_of_separability.py

@@ -27,13 +27,18 @@
 
 mixed_rho = max_mixed(8, is_sparse=False)
 
-@pytest.mark.parametrize("test_input, input_dim, expected_msg, expected_error", [
-    (bad_rho, [2, 2, 2], "Provided input state is not a density matrix.", ValueError),
-    (purification_state, [2, 2], "For Channel SDP: require tripartite state dims.", AssertionError),
-    (mixed_rho, [2, 2, 2], "This function only works for pure states.", ValueError)])
+
+@pytest.mark.parametrize(
+    "test_input, input_dim, expected_msg, expected_error",
+    [
+        (bad_rho, [2, 2, 2], "Provided input state is not a density matrix.", ValueError),
+        (purification_state, [2, 2], "For Channel SDP: require tripartite state dims.", AssertionError),
+        (mixed_rho, [2, 2, 2], "This function only works for pure states.", ValueError),
+    ],
+)
 def test_errors_channel_SDP(test_input, input_dim, expected_msg, expected_error):
     """Tests for raised errors in channel SDP function."""
-    with pytest.raises(expected_error, match = expected_msg):
+    with pytest.raises(expected_error, match=expected_msg):
         fidelity_of_separability(test_input, input_dim)
 
 

toqito/channel_ops/__init__.py

@@ -1,4 +1,5 @@
 """A number of operations on quantum channels."""
+
 from toqito.channel_ops.apply_channel import apply_channel
 from toqito.channel_ops.partial_channel import partial_channel
 from toqito.channel_ops.choi_to_kraus import choi_to_kraus

toqito/channel_ops/apply_channel.py

@@ -1,6 +1,5 @@
 """Apply channel to an operator."""
 
-
 import itertools
 
 import numpy as np
@@ -147,7 +146,4 @@ def apply_channel(mat: np.ndarray, phi_op: np.ndarray | list[list[np.ndarray]])
             order="F",
         )
         return a_mat @ b_mat
-    raise ValueError(
-        "Invalid: The variable `phi_op` must either be a list of "
-        "Kraus operators or as a Choi matrix."
-    )
+    raise ValueError("Invalid: The variable `phi_op` must either be a list of Kraus operators or as a Choi matrix.")

toqito/channel_ops/choi_to_kraus.py

@@ -1,6 +1,5 @@
 """Compute a list of Kraus operators from the Choi matrix."""
 
-
 import numpy as np
 
 from toqito.helper import channel_dim
@@ -108,8 +107,7 @@ def choi_to_kraus(
             return kraus_0
 
         kraus_1 = [
-            np.sign(eigval) * k_mat
-            for eigval, k_mat in zip(filter(lambda eigval: abs(eigval) > tol, eigvals), kraus_0)
+            np.sign(eigval) * k_mat for eigval, k_mat in zip(filter(lambda eigval: abs(eigval) > tol, eigvals), kraus_0)
         ]
     else:
         u_mat, singular_values, vh_mat = np.linalg.svd(choi_mat, full_matrices=False)

toqito/channel_ops/dual_channel.py

@@ -1,6 +1,5 @@
 """Compute the dual of a map."""
 
-
 import numpy as np
 
 from toqito.helper import channel_dim
@@ -95,7 +94,4 @@ def dual_channel(
         if len(phi_op.shape) == 2:
             d_in, d_out, _ = channel_dim(phi_op, dim=dims, compute_env_dim=False)
             return swap(phi_op.conj(), dim=[[d_in[0], d_out[0]], [d_in[1], d_out[1]]])
-    raise ValueError(
-        "Invalid: The variable `phi_op` must either be a list of "
-        "Kraus operators or as a Choi matrix."
-    )
+    raise ValueError("Invalid: The variable `phi_op` must either be a list of Kraus operators or as a Choi matrix.")

toqito/channel_ops/kraus_to_choi.py

@@ -1,4 +1,5 @@
 """Compute the Choi matrix of a list of Kraus operators."""
+
 import numpy as np
 
 from toqito.channel_ops import partial_channel