Pivot to using ruff for all linting (#15603)

* Pivot to using ruff for all linting

This commit switches us to fully using ruff for all the linting in CI
and locally. The primary motivation for this change is to improve
productivity because ruff is signficantly faster. Pylint is incredibly
slow in general, but compared to ruff especially so. For example, on my
laptop ruff takes 0.04 seconds to run on the qiskit/ subdirectory (after
clearing the cache, with the cache populated it takes 0.025 sec) of the
source tree while running pylint on the same path took 70 sec. This leads
to people skipping lint locally and causes churn in CI becaus.

We had started to experimenting with ruff in the past and
used it for a some small set of rules but were still using pylint for
the bulk of the linting in the repo. The concern at the time was a loss
of lint coverage or a lot of code churn caused by migrating to a new tool.
Specifically pylint does more type inference and checking that ruff
doesn't. However since we started the experiment one major change in
qiskit is how much work is happening in rust now vs Python. At this
point any loss in lint coverage is unlikely to cause a significant
problem in practice and we'll make real productivity gains by making
this change.

* Remove out of date comment

* Update makefile

* Enable more rules

* Revert lambda autofixes

* Fix new rules

* Add bandit rules

* Enable Ruff native rules

* Remove pylint disable comments

* Enable docstring rules

This commit adds the docstring rules on the repo. This involves a few
more changes than previous commits because there are a lot of formatting
consistency rules that needed to be auto-applied. The checking also
found several instances where there was missing documentation that
should have been included.

* Add categories from old ruff config

* Fix from rebase

* Add flake8-raise rule

* Add flake8-pie rules

* Add implicit namespace rules

* Fix deprecation decorator error on import

* Fix __init__ docstring for deprecated circuit library elements

* Revert "Enable docstring rules"

The formatting changes that ruff auto applied to the docstrings were not
valid in many cases. The changeset for the commit was too large to
systematically revert just the incorrect autoformatting and disabling
those rules. Instead this reverts commit
f928646 on the whole. We can circle back
and add a reduced subset of the docstring rules that makes sense and a
functional docs build after the revert.

* Fix typo in latex circuit drawer changes

* Fix csp tests for rng change

* Remove unused typing imports

* Bump to ruff 0.15.2

Since this PR was first opened there have been several new ruff
releases. This updates to the latest release as of this commit. The
0.15.0 release included a new default rule in the RUF ruleset which
triggered on the code base which this also fixes.

Author: mtreinish

CONTRIBUTING.md

@@ -787,26 +787,18 @@ int test_FILE_NAME()
 Qiskit uses three tools for Python code formatting and lint checking. The
 first tool is [black](https://github.com/psf/black) which is a code formatting
 tool that will automatically update the code formatting to a consistent style.
-The second tool is [pylint](https://www.pylint.org/) which is a code linter
+The second tool is [ruff](https://docs.astral.sh/ruff/) which is a code linter
 which does a deeper analysis of the Python code to find both style issues and
-potential bugs and other common issues in Python. The third tool is the linter
-[ruff](https://github.com/charliermarsh/ruff), which has been recently
-introduced into Qiskit on an experimental basis. Only a very small number
-of rules are enabled.
+potential bugs and other common issues in Python.
 
 You can check that your local modifications conform to the style rules by
-running `tox -elint` which will run `black`, `ruff`, and `pylint` to check the
+running `tox -elint` which will run `black` and  `ruff` to check the
 local code formatting and lint. If black returns a code formatting error you can
 run `tox -eblack` to automatically update the code formatting to conform to the
-style. However, if `ruff` or `pylint` return any error you will have to fix
-these issues by manually updating your code.
-
-Because `pylint` analysis can be slow, there is also a `tox -elint-incr` target,
-which runs `black` and `ruff` just as `tox -elint` does, but only applies
-`pylint` to files which have changed from the source github. On rare occasions
-this will miss some issues that would have been caught by checking the complete
-source tree, but makes up for this by being much faster (and those rare
-oversights will still be caught by the CI after you open a pull request).
+style. However, if `ruff`  return any error you will have to fix these issues by
+manually updating your code. Sometimes `ruff` will be able to fix failures with
+the `--fix` flag. In these cases the output will tell you how many errors can be
+automatically fixed
 
 Because they are so fast, it is sometimes convenient to run the tools `black` and `ruff` separately
 rather than via `tox`.  You can install all the lint dependencies using the `lint` or `dev`

Makefile

@@ -16,7 +16,7 @@ endif
 
 .PHONY: default ruff env lint lint-incr style black test test_randomized pytest pytest_randomized test_ci coverage coverage_erase clean
 
-default: ruff style lint-incr test ;
+default: style lint-incr test ;
 
 # Dependencies need to be installed on the Anaconda virtual environment.
 env:
@@ -27,18 +27,15 @@ env:
 		bash -c "source activate Qiskitenv;pip install -r requirements.txt"; \
 	fi;
 
-# Ignoring generated ones with .py extension.
 lint:
-	pylint -rn qiskit test tools
+	ruff check qiskit test tools setup.py
 	tools/verify_headers.py qiskit test tools
 	tools/find_optional_imports.py
 	tools/find_stray_release_notes.py
 	tools/verify_images.py
 
-# Only pylint on files that have changed from origin/main. Also parallelize (disables cyclic-import check)
 lint-incr:
-	-git fetch -q https://github.com/Qiskit/qiskit-terra.git :lint_incr_latest
-	tools/pylint_incr.py -j4 -rn -sn --paths :/qiskit/*.py :/test/*.py :/tools/*.py
+	ruff check qiskit test tools setup.py
 	tools/verify_headers.py qiskit test tools
 	tools/find_optional_imports.py
 	tools/verify_images.py

pyproject.toml

@@ -188,9 +188,7 @@ build = ["setuptools>=77.0", "setuptools-rust"]
 # We use quite tight pins on pylint and astroid because they have a habit of adding new
 # on-by-default lints that are harder to deal with.
 lint = [
-    "pylint~=3.2.0",
-    "astroid~=3.2.0",
-    "ruff==0.0.267",
+    "ruff==0.15.2",
     "reno>=4.1.0",  # duplicated with `doc`
     "black[jupyter]~=25.1",
 ]
@@ -312,17 +310,180 @@ test-command = "cp -r {project}/test . && stestr --test-path test/python run --a
 repair-wheel-command = "cp {wheel} {dest_dir}/. && pipx run abi3audit --strict --report {wheel}"
 
 [tool.ruff]
+line-length = 110
+
+[tool.ruff.lint]
 select = [
-  # Rules in alphabetic order
-  "C4",    # category: flake8-comprehensions
-  "EXE",   # Category: flake8-executable
-  "F631",  # assert-tuple
-  "F632",  # is-literal
-  "F634",  # if-tuple
-  "F823",  # undefined-local
-  "G",     # flake8-logging-format
-  "T10",   # category: flake8-debugger
+    # pycodestyle
+    "E",
+    # Pyflakes
+    "F",
+    # Pylint
+    "PL",
+    # pyupgrade
+    "UP",
+    # bandit
+    "S",
+    # Ruff native rules
+    "RUF",
+    # flake8-logging-format
+    "G",
+    # flake8-executable
+    "EXE",
+    # flake8-comprehensions
+    "C4",
+    # flake8-debugger
+    "T10",
+    # flake8-raise
+    "RSE",
+    # flake8-pie
+    "PIE",
+    # flake8-no-pep420
+    "INP",
+]
+ignore = [
+    "E402",  # module-import-not-at-top-of-file false positives with module docs
+    "F401",  # unused-import false triggers on init re-exports with __all__
+    "E501",  # line-too-long rely on black for formatting
+    "PLR2004",  # magic-value-comparison overly pedantic especially in tests
+    "PLR0911",  # too-many-return-statements
+    "PLR0912",  # too-many-branches
+    "PLR0904",  # too-many-public-methods
+    "PLR0914",  # too-many-locals
+    "PLR0915",  # too-many-statements
+    "PLR1702",  # too-many-nested-blocks
+    "PLR0904",  # too-many-public-methods
+    "PLC0415",  # import-outside-top-level
+    "E731",     # lambda-assignment
+    "PLW1514",  # unspecified-encoding do not want to implement
+    "PLR0913",  # too-many-arguments
+    "PLW1641",  # eq-without-hash  not everything has to be hashablie
+    "PLW3301",  # nested-min-max
+    "PLW2901",  # redefined-loop-variablke - TODO fix this
+    "RUF003",   # ambiguous-unicode-character-comment
+    "RUF005",   # collection-literal-concatenation
+    "RUF012",   # mutable-class-default"
+    "RUF001",   # ambiguous-unicode-character-string
+    "RUF002",   # ambiguous-unicode-character-docstring
+    "RUF007",   # zip-instead-of-pairwise overly opinionated
+]
+
+[tool.ruff.lint.per-file-ignores]
+"*.ipynb" = ["F821"]
+# Security rules from bandit don't apply to tests and utils
+"tools/*" = [
+    "S603",
+# Docstring rules don't apply to tools as they're not documented
+    "D100",
+    "D101",
+    "D102",
+    "D103",
+    "D104",
+    "D105",
+    "D106",
+    "D107",
+    "D200",
+    "D201",
+    "D202",
+    "D203",
+    "D204",
+    "D205",
+    "D206",
+    "D207",
+    "D208",
+    "D209",
+    "D210",
+    "D211",
+    "D212",
+    "D213",
+    "D214",
+    "D215",
+    "D300",
+    "D301",
+    "D400",
+    "D401",
+    "D402",
+    "D403",
+    "D404",
+    "D405",
+    "D406",
+    "D407",
+    "D408",
+    "D409",
+    "D410",
+    "D411",
+    "D412",
+    "D413",
+    "D414",
+    "D415",
+    "D416",
+    "D417",
+    "D418",
+    "D419",
+# Implicit namespace rules don't apply to tools because they're all standalone scripts
+    "INP001",
+]
+"test/*" = [
+    "S110",
+    "S301",
+    "S603",
+    "S311",
+    "S307",
+    "RUF015",
+# Docstring rules don't apply to tests as they're not documented
+    "D100",
+    "D101",
+    "D102",
+    "D103",
+    "D104",
+    "D105",
+    "D106",
+    "D107",
+    "D200",
+    "D201",
+    "D202",
+    "D203",
+    "D204",
+    "D205",
+    "D206",
+    "D207",
+    "D208",
+    "D209",
+    "D210",
+    "D211",
+    "D212",
+    "D213",
+    "D214",
+    "D215",
+    "D300",
+    "D301",
+    "D400",
+    "D401",
+    "D402",
+    "D403",
+    "D404",
+    "D405",
+    "D406",
+    "D407",
+    "D408",
+    "D409",
+    "D410",
+    "D411",
+    "D412",
+    "D413",
+    "D414",
+    "D415",
+    "D416",
+    "D417",
+    "D418",
+    "D419",
 ]
+"test/randomized/*" = ["S101"]
+"test/qpy_compat/*" = ["S101", "INP001"]
+"test/benchmarks/*" = ["S101"]
+# Visualization functions often subprocess to visualization tools
+"qiskit/visualization/*" = ["S603", "S607"]
+
 
 [tool.pylint.main]
 extension-pkg-allow-list = [
@@ -354,22 +515,19 @@ disable = [
     "protected-access", # disabled as we don't follow the public vs private convention strictly
     "duplicate-code", # disabled as it is too verbose
     "redundant-returns-doc", # for @abstractmethod, it cannot interpret "pass"
-    "too-many-lines", "too-many-branches", "too-many-locals", "too-many-nested-blocks", "too-many-statements",
-    "too-many-instance-attributes", "too-many-arguments", "too-many-public-methods", "too-few-public-methods", "too-many-ancestors",
+    "too-many-instance-attributes", "too-many-arguments", "too-few-public-methods", "too-many-ancestors",
     "unnecessary-pass", # allow for methods with just "pass", for clarity
     "unnecessary-dunder-call", # do not want to implement
     "no-else-return",  # relax "elif" after a clause with a return
     "docstring-first-line-empty", # relax docstring style
     "import-outside-toplevel", "import-error", # overzealous with our optionals/dynamic packages
-    "nested-min-max", # this gives false equivalencies if implemented for the current lint version
     "consider-using-max-builtin", "consider-using-min-builtin",  # unnecessary stylistic opinion
 # TODO(#9614): these were added in modern Pylint. Decide if we want to enable them. If so,
 #  remove from here and fix the issues. Else, move it above this section and add a comment
 #  with the rationale
     "no-member",  # for dynamically created members
     "not-context-manager",
     "unnecessary-lambda-assignment",  # do not want to implement
-    "unspecified-encoding",  # do not want to implement
 ]
 
 enable = [

qiskit/__init__.py

@@ -10,7 +10,6 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
-# pylint: disable=wrong-import-position,wrong-import-order
 
 # The documentation of the root namespace is manual in `docs/apidoc/root.rst`, so that the
 # :mod:`qiskit` Sphinx cross-reference can more easily point to the top-level API table in our
@@ -34,7 +33,7 @@
     # `qiskit/tools` folder in their path, which will appear as a "namespace package" with no valid
     # location.  We catch that case as "not actually having Qiskit 0.x" as a convenience to devs.
     _has_tools = getattr(importlib.util.find_spec("qiskit.tools"), "has_location", False)
-    _suppress_error = os.environ.get("QISKIT_SUPPRESS_1_0_IMPORT_ERROR", False) == "1"
+    _suppress_error = os.environ.get("QISKIT_SUPPRESS_1_0_IMPORT_ERROR", "") == "1"
     if not _suppress_error and _has_tools:
         raise ImportError(
             "Qiskit is installed in an invalid environment that has both Qiskit >=1.0"
@@ -172,6 +171,6 @@
     "QiskitError",
     "QuantumCircuit",
     "QuantumRegister",
-    "transpile",
     "generate_preset_pass_manager",
+    "transpile",
 ]

qiskit/_numpy_compat.py

@@ -53,7 +53,7 @@
 """
 
 VERSION = np.lib.NumpyVersion(np.__version__)
-VERSION_PARTS: typing.Tuple[int, ...]
+VERSION_PARTS: tuple[int, ...]
 """The numeric parts of the Numpy release version, e.g. ``(2, 0, 0)``.  Does not include pre- or
 post-release markers (e.g. ``rc1``)."""
 if match := re.fullmatch(_VERSION_PATTERN, np.__version__, flags=re.VERBOSE | re.IGNORECASE):

qiskit/circuit/__init__.py

@@ -1374,7 +1374,7 @@ def __array__(self, dtype=None, copy=None):
         \end{pmatrix}
 """
 
-from qiskit._accelerate.circuit import (  # pylint: disable=unused-import
+from qiskit._accelerate.circuit import (
     Bit,
     Qubit,
     AncillaQubit,
@@ -1391,7 +1391,7 @@ def __array__(self, dtype=None, copy=None):
 from .quantumcircuit import QuantumCircuit
 from .gate import Gate
 
-# pylint: disable=cyclic-import
+
 from . import annotation
 from .annotation import Annotation
 from .controlledgate import ControlledGate

qiskit/circuit/_add_control.py

@@ -127,7 +127,6 @@ def control(
         CircuitError: gate contains non-gate in definition
     """
 
-    # pylint: disable=cyclic-import
     from qiskit.circuit import controlledgate
 
     ctrl_state = _ctrl_state_to_int(ctrl_state, num_ctrl_qubits)
@@ -262,23 +261,22 @@ def apply_basic_controlled_gate(circuit, gate, controls, target):
                 circuit.cp(lamb, controls[0], target)
             else:
                 circuit.cu(theta, phi, lamb, 0, controls[0], target)
+        elif phi == -pi / 2 and lamb == pi / 2:
+            circuit.mcrx(theta, controls, target, use_basis_gates=False)
+        elif phi == 0 and lamb == 0:
+            circuit.mcry(
+                theta,
+                controls,
+                target,
+                use_basis_gates=False,
+            )
+        elif theta == 0 and phi == 0:
+            circuit.mcp(lamb, controls, target)
         else:
-            if phi == -pi / 2 and lamb == pi / 2:
-                circuit.mcrx(theta, controls, target, use_basis_gates=False)
-            elif phi == 0 and lamb == 0:
-                circuit.mcry(
-                    theta,
-                    controls,
-                    target,
-                    use_basis_gates=False,
-                )
-            elif theta == 0 and phi == 0:
-                circuit.mcp(lamb, controls, target)
-            else:
-                circuit.mcrz(lamb, controls, target, use_basis_gates=False)
-                circuit.mcry(theta, controls, target, use_basis_gates=False)
-                circuit.mcrz(phi, controls, target, use_basis_gates=False)
-                circuit.mcp((phi + lamb) / 2, controls[1:], controls[0])
+            circuit.mcrz(lamb, controls, target, use_basis_gates=False)
+            circuit.mcry(theta, controls, target, use_basis_gates=False)
+            circuit.mcrz(phi, controls, target, use_basis_gates=False)
+            circuit.mcp((phi + lamb) / 2, controls[1:], controls[0])
 
     elif gate.name == "z":
         circuit.h(target)