Fix coverage exclusion syntax

CONTRIBUTING.md

@@ -1,9 +1,9 @@
 # How to Contribute
 
 We'd love to accept your patches and contributions to this project.
-We do have some guidelines to follow, covered in this document, but don't 
+We do have some guidelines to follow, covered in this document, but don't
 worry about (or expect to) get everything right the first time!
-Create a pull request and we'll nudge you in the right direction. Please also 
+Create a pull request and we'll nudge you in the right direction. Please also
 note that we have a [code of conduct](CODE_OF_CONDUCT.md) to make Cirq an
 open and welcoming environment.
 
@@ -83,7 +83,7 @@ on setting up your local development environment.
 
 ## Code Testing Standards
 
-When a pull request is created or updated, various automatic checks will 
+When a pull request is created or updated, various automatic checks will
 run to ensure that the change won't break Cirq and meets our coding standards.
 
 Cirq contains a continuous integration tool to verify testing.  See our
@@ -94,36 +94,36 @@ Please be aware of the following code standards that will be applied to any
 new changes.
 
 - **Tests**.
-Existing tests must continue to pass (or be updated) when new changes are 
-introduced. We use [pytest](https://docs.pytest.org/en/latest/) to run our 
+Existing tests must continue to pass (or be updated) when new changes are
+introduced. We use [pytest](https://docs.pytest.org/en/latest/) to run our
 tests.
 - **Coverage**.
 Code should be covered by tests.
-We use [pytest-cov](https://pytest-cov.readthedocs.io/en/latest/) to compute 
+We use [pytest-cov](https://pytest-cov.readthedocs.io/en/latest/) to compute
 coverage, and custom tooling to filter down the output to only include new or
-changed code. We don't require 100% coverage, but any uncovered code must 
-be annotated with `# coverage: ignore`. To ignore coverage of a single line, 
-place `# coverage: ignore` at the end of the line. To ignore coverage for 
-an entire block, start the block with a `# coverage: ignore` comment on its 
+changed code. We don't require 100% coverage, but any uncovered code must
+be annotated with `# pragma: no cover`. To ignore coverage of a single line,
+place `# pragma: no cover` at the end of the line. To ignore coverage for
+an entire block, start the block with a `# pragma: no cover` comment on its
 own line.
 - **Lint**.
-Code should meet common style standards for python and be free of error-prone 
+Code should meet common style standards for python and be free of error-prone
 constructs. We use [pylint](https://www.pylint.org/) to check for lint.
-To see which lint checks we enforce, see the 
+To see which lint checks we enforce, see the
 [dev_tools/conf/.pylintrc](dev_tools/conf/.pylintrc) file. When pylint produces
-a false positive, it can be squashed with annotations like 
+a false positive, it can be squashed with annotations like
 `# pylint: disable=unused-import`.
 - **Types**.
 Code should have [type annotations](https://www.python.org/dev/peps/pep-0484/).
 We use [mypy](http://mypy-lang.org/) to check that type annotations are correct.
-When type checking produces a false positive, it can be ignored with 
+When type checking produces a false positive, it can be ignored with
 annotations like `# type: ignore`.
 
 ## Request For Comment Process for New Major Features
 
-For larger contributions that will benefit from design reviews, please use the 
+For larger contributions that will benefit from design reviews, please use the
 [Request for Comment](docs/dev/rfc_process.md) process.
 
-## Developing notebooks 
+## Developing notebooks
 
-Please refer to our [notebooks guide](docs/dev/notebooks.md) on how to develop iPython notebooks for documentation.
+Please refer to our [notebooks guide](docs/dev/notebooks.md) on how to develop iPython notebooks for documentation.

cirq-core/cirq/_version.py

@@ -17,8 +17,7 @@
 
 import sys
 
-if sys.version_info < (3, 9, 0):
-    # coverage: ignore
+if sys.version_info < (3, 9, 0):  # pragma: no cover
     raise SystemError(
         "You installed the latest version of cirq but aren't on python 3.9+.\n"
         'To fix this error, you need to either:\n'

cirq-core/cirq/circuits/circuit_operation.py

@@ -61,9 +61,9 @@ def _full_join_string_lists(
     list1: Optional[Sequence[str]], list2: Optional[Sequence[str]]
 ) -> Optional[Sequence[str]]:
     if list1 is None and list2 is None:
-        return None  # coverage: ignore
+        return None  # pragma: no cover
     if list1 is None:
-        return list2  # coverage: ignore
+        return list2  # pragma: no cover
     if list2 is None:
         return list1
     return [f'{first}{REPETITION_ID_SEPARATOR}{second}' for first in list1 for second in list2]

cirq-core/cirq/circuits/qasm_output_test.py

@@ -257,7 +257,7 @@ def _qasm_(self, args: cirq.QasmArgs) -> str:
 
         def _decompose_(self):
             # Only used by test_output_unitary_same_as_qiskit
-            return ()  # coverage: ignore
+            return ()  # pragma: no cover
 
     class DummyCompositeOperation(cirq.Operation):
         qubits = (q0,)

cirq-core/cirq/conftest.py

@@ -27,8 +27,7 @@ def pytest_configure(config):
 
 def pytest_pyfunc_call(pyfuncitem):
     if inspect.iscoroutinefunction(pyfuncitem._obj):
-        # coverage: ignore
-        raise ValueError(
+        raise ValueError(  # pragma: no cover
             f'{pyfuncitem._obj.__name__} is a bare async function. '
             f'It should be decorated with "@duet.sync".'
         )

cirq-core/cirq/contrib/acquaintance/devices.py

@@ -68,7 +68,7 @@ class _UnconstrainedAcquaintanceDevice(AcquaintanceDevice):
     """An acquaintance device with no constraints other than of the gate types."""
 
     def __repr__(self) -> str:
-        return 'UnconstrainedAcquaintanceDevice'  # coverage: ignore
+        return 'UnconstrainedAcquaintanceDevice'  # pragma: no cover
 
 
 UnconstrainedAcquaintanceDevice = _UnconstrainedAcquaintanceDevice()

cirq-core/cirq/contrib/hacks/disable_validation_test.py

@@ -29,7 +29,7 @@ def test_disable_op_validation():
     with pytest.raises(ValueError, match='mysterious and terrible'):
         with disable_op_validation():
             # This does not run - the with condition errors out first.
-            _ = cirq.H(q0, q1)  # coverage: ignore
+            _ = cirq.H(q0, q1)  # pragma: no cover
 
     # Passes, skipping validation.
     with disable_op_validation(accept_debug_responsibility=True):

cirq-core/cirq/contrib/noise_models/noise_models.py

@@ -41,8 +41,7 @@ def __init__(self, depol_prob: float, prepend: bool = False):
         self._prepend = prepend
 
     def noisy_moment(self, moment: 'cirq.Moment', system_qubits: Sequence['cirq.Qid']):
-        if validate_all_measurements(moment) or self.is_virtual_moment(moment):
-            # coverage: ignore
+        if validate_all_measurements(moment) or self.is_virtual_moment(moment):  # pragma: no cover
             return moment
 
         output = [

cirq-core/cirq/contrib/paulistring/clifford_optimize.py

@@ -161,7 +161,7 @@ def try_merge_cz(cz_op: ops.GateOperation, start_i: int) -> int:
             else:
                 # Two CZ gates that share one qubit
                 # Pass through and keep looking
-                continue  # coverage: ignore
+                continue  # pragma: no cover
                 # The above line is covered by test_remove_staggered_czs but the
                 # coverage checker disagrees.
         return 0

cirq-core/cirq/contrib/qcircuit/qcircuit_pdf.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# coverage: ignore
+# pragma: no cover
 
 import errno
 import os

cirq-core/cirq/contrib/quimb/density_matrix.py

@@ -106,8 +106,7 @@ def circuit_to_density_matrix_tensors(
         ValueError: If an op is encountered that cannot be converted.
     """
     if qubits is None:
-        # coverage: ignore
-        qubits = sorted(circuit.all_qubits())
+        qubits = sorted(circuit.all_qubits())  # pragma: no cover
     qubits = tuple(qubits)
 
     qubit_frontier: Dict[cirq.Qid, int] = {q: 0 for q in qubits}
@@ -190,7 +189,7 @@ def _positions(_mi, _these_qubits):
                 )
                 kraus_frontier += 1
             else:
-                raise ValueError(repr(op))  # coverage: ignore
+                raise ValueError(repr(op))  # pragma: no cover
 
             _positions(mi + 1, op.qubits)
     return tensors, qubit_frontier, positions

cirq-core/cirq/contrib/quimb/grid_circuits.py

@@ -54,12 +54,12 @@ def _interaction(
             for col in range(col_start + col_start_offset, col_end + col_end_offset, col_step):
                 node1 = (row, col)
                 if node1 not in problem_graph.nodes:
-                    continue  # coverage: ignore
+                    continue  # pragma: no cover
                 node2 = get_neighbor(row, col)
                 if node2 not in problem_graph.nodes:
-                    continue  # coverage: ignore
+                    continue  # pragma: no cover
                 if (node1, node2) not in problem_graph.edges:
-                    continue  # coverage: ignore
+                    continue  # pragma: no cover
 
                 weight = problem_graph.edges[node1, node2].get('weight', 1)
                 yield two_qubit_gate(exponent=weight, global_shift=-0.5).on(

cirq-core/cirq/contrib/quimb/state_vector.py

@@ -9,7 +9,6 @@
 import cirq
 
 
-# coverage: ignore
 def _get_quimb_version():
     """Returns the quimb version and parsed (major,minor) numbers if possible.
     Returns:
@@ -18,7 +17,7 @@ def _get_quimb_version():
     version = quimb.__version__
     try:
         return tuple(int(x) for x in version.split('.')), version
-    except:
+    except:  # pragma: no cover
         return (0, 0), version
 
 
@@ -59,7 +58,7 @@ def circuit_to_tensors(
             corresponding to the |0> state.
     """
     if qubits is None:
-        qubits = sorted(circuit.all_qubits())  # coverage: ignore
+        qubits = sorted(circuit.all_qubits())  # pragma: no cover
 
     qubit_frontier = {q: 0 for q in qubits}
     positions = None
@@ -163,8 +162,7 @@ def tensor_expectation_value(
     ]
     tn = qtn.TensorNetwork(tensors + end_bras)
     if QUIMB_VERSION[0] < (1, 3):
-        # coverage: ignore
-        warnings.warn(
+        warnings.warn(  # pragma: no cover
             f'quimb version {QUIMB_VERSION[1]} detected. Please use '
             f'quimb>=1.3 for optimal performance in '
             '`tensor_expectation_value`. '

cirq-core/cirq/contrib/routing/utils.py

@@ -96,8 +96,7 @@ def get_circuit_connectivity(circuit: 'cirq.Circuit') -> nx.Graph:
     for op in circuit.all_operations():
         n_qubits = len(op.qubits)
         if n_qubits > 2:
-            # coverage: ignore
-            raise ValueError(
+            raise ValueError(  # pragma: no cover
                 f"Cannot build a graph out of a circuit that "
                 f"contains {n_qubits}-qubit operations"
             )

cirq-core/cirq/contrib/svg/svg.py

@@ -140,12 +140,11 @@ def _fit_vertical(
     return row_starts, row_heights, yi_map
 
 
-def _debug_spacing(col_starts, row_starts):
+def _debug_spacing(col_starts, row_starts):  # pragma: no cover
     """Return a string suitable for inserting inside an <svg> tag that
     draws green lines where columns and rows start. This is very useful
     if you're developing this code and are debugging spacing issues.
     """
-    # coverage: ignore
     t = ''
     for i, cs in enumerate(col_starts):
         t += (
@@ -198,7 +197,6 @@ def tdd_to_svg(
             # qubits start at far left and their wires shall be blue
             stroke = QBLUE
         else:
-            # coverage: ignore
             stroke = 'black'
         t += f'<line x1="{x1}" x2="{x2}" y1="{y}" y2="{y}" stroke="{stroke}" stroke-width="1" />'
 
@@ -261,11 +259,9 @@ class SVGCircuit:
     """
 
     def __init__(self, circuit: 'cirq.Circuit'):
-        # coverage: ignore
         self.circuit = circuit
 
     def _repr_svg_(self) -> str:
-        # coverage: ignore
         return circuit_to_svg(self.circuit)
 
 

cirq-core/cirq/devices/named_topologies.py

@@ -93,7 +93,7 @@ def draw_gridlike(
         to NetworkX plotting functionality.
     """
     if ax is None:
-        ax = plt.gca()  # coverage: ignore
+        ax = plt.gca()  # pragma: no cover
 
     if tilted:
         pos = {node: (y, -x) for node, (x, y) in _node_and_coordinates(graph.nodes)}
@@ -295,8 +295,7 @@ def get_placements(
     for big_to_small_map in matcher.subgraph_monomorphisms_iter():
         dedupe[frozenset(big_to_small_map.keys())] = big_to_small_map
         if len(dedupe) > max_placements:
-            # coverage: ignore
-            raise ValueError(
+            raise ValueError(  # pragma: no cover
                 f"We found more than {max_placements} placements. Please use a "
                 f"more constraining `big_graph` or a more constrained `small_graph`."
             )
@@ -367,27 +366,23 @@ def draw_placements(
             this callback is called. The callback should accept `ax` and `i` keyword arguments
             for the current axis and mapping index, respectively.
     """
-    if len(small_to_big_mappings) > max_plots:
-        # coverage: ignore
+    if len(small_to_big_mappings) > max_plots:  # pragma: no cover
         warnings.warn(f"You've provided a lot of mappings. Only plotting the first {max_plots}")
         small_to_big_mappings = small_to_big_mappings[:max_plots]
 
     call_show = False
     if axes is None:
-        # coverage: ignore
-        call_show = True
+        call_show = True  # pragma: no cover
 
     for i, small_to_big_map in enumerate(small_to_big_mappings):
         if axes is not None:
             ax = axes[i]
-        else:
-            # coverage: ignore
+        else:  # pragma: no cover
             ax = plt.gca()
 
         small_mapped = nx.relabel_nodes(small_graph, small_to_big_map)
         if bad_placement_callback is not None:
-            # coverage: ignore
-            if not _is_valid_placement_helper(
+            if not _is_valid_placement_helper(  # pragma: no cover
                 big_graph=big_graph,
                 small_mapped=small_mapped,
                 small_to_big_mapping=small_to_big_map,
@@ -406,7 +401,6 @@ def draw_placements(
         )
         ax.axis('equal')
         if call_show:
-            # coverage: ignore
             # poor man's multi-axis figure: call plt.show() after each plot
             # and jupyter will put the plots one after another.
-            plt.show()
+            plt.show()  # pragma: no cover

cirq-core/cirq/devices/noise_properties.py

@@ -97,7 +97,7 @@ def noisy_moments(
             # only ops with PHYSICAL_GATE_TAG will receive noise.
             if virtual_ops:
                 # Only subclasses will trigger this case.
-                new_moments.append(circuits.Moment(virtual_ops))  # coverage: ignore
+                new_moments.append(circuits.Moment(virtual_ops))  # pragma: no cover
             if physical_ops:
                 new_moments.append(circuits.Moment(physical_ops))
 

cirq-core/cirq/experiments/readout_confusion_matrix.py

@@ -278,7 +278,7 @@ def apply(
             raise ValueError(f"method: {method} should be 'pseudo_inverse' or 'least_squares'.")
 
         if method == 'pseudo_inverse':
-            return result @ self.correction_matrix(qubits)  # coverage: ignore
+            return result @ self.correction_matrix(qubits)  # pragma: no cover
 
         # Least squares minimization.
         cm = self.confusion_matrix(qubits)
@@ -291,11 +291,11 @@ def func(x):
         res = scipy.optimize.minimize(
             func, result, method='SLSQP', constraints=constraints, bounds=bounds
         )
-        if res.success is False:  # coverage: ignore
-            raise ValueError(  # coverage: ignore
-                f"SLSQP optimization for constrained minimization "  # coverage: ignore
-                f"did not converge. Result:\n{res}"  # coverage: ignore
-            )  # coverage: ignore
+        if res.success is False:  # pragma: no cover
+            raise ValueError(  # pragma: no cover
+                f"SLSQP optimization for constrained minimization "  # pragma: no cover
+                f"did not converge. Result:\n{res}"  # pragma: no cover
+            )  # pragma: no cover
         return res.x
 
     def __repr__(self) -> str:

cirq-core/cirq/experiments/xeb_fitting.py

@@ -108,12 +108,11 @@ def per_cycle_depth(df):
         def _try_keep(k):
             """If all the values for a key `k` are the same in this group, we can keep it."""
             if k not in df.columns:
-                return  # coverage: ignore
+                return  # pragma: no cover
             vals = df[k].unique()
             if len(vals) == 1:
                 ret[k] = vals[0]
-            else:
-                # coverage: ignore
+            else:  # pragma: no cover
                 raise AssertionError(
                     f"When computing per-cycle-depth fidelity, multiple "
                     f"values for {k} were grouped together: {vals}"
@@ -574,8 +573,7 @@ def _fit_exponential_decay(
             p0=(a_0, layer_fid_0),
             bounds=((0, 0), (1, 1)),
         )
-    except ValueError:  # coverage: ignore
-        # coverage: ignore
+    except ValueError:  # pragma: no cover
         return 0, 0, np.inf, np.inf
 
     a_std, layer_fid_std = np.sqrt(np.diag(pcov))