Enable ruff flake8-bugbear rule (#2536)

Co-authored-by: Manuel Schlund <[email protected]>

doc/contributing.rst

@@ -609,7 +609,7 @@ that feature should be removed in version 2.7:
                "ESMValCore version 2.5 and is scheduled for removal in "
                "version 2.7. Add additional text (e.g., description of "
                "alternatives) here.")
-           warnings.warn(deprecation_msg, ESMValCoreDeprecationWarning)
+           warnings.warn(deprecation_msg, ESMValCoreDeprecationWarning, stacklevel=2)
 
        # Other code
 

doc/recipe/preprocessor.rst

@@ -611,7 +611,7 @@ See also :func:`esmvalcore.preprocessor.weighting_landsea_fraction`.
 .. _masking:
 
 Masking
-=======
+========
 
 Introduction to masking
 -----------------------
@@ -2451,7 +2451,7 @@ See also :func:`esmvalcore.preprocessor.linear_trend_stderr`.
 .. _detrend:
 
 Detrend
-=======
+========
 
 ESMValCore also supports detrending along any dimension using
 the preprocessor function 'detrend'.

esmvalcore/_recipe/check.py

@@ -44,12 +44,12 @@ def ncl_version():
     try:
         cmd = [ncl, "-V"]
         version = subprocess.check_output(cmd, universal_newlines=True)
-    except subprocess.CalledProcessError:
-        logger.error("Failed to execute '%s'", " ".join(" ".join(cmd)))
+    except subprocess.CalledProcessError as exc:
+        logger.error("Failed to execute '%s'", " ".join(cmd))
         raise RecipeError(
             "Recipe contains NCL scripts, but your NCL "
             "installation appears to be broken."
-        )
+        ) from exc
 
     version = version.strip()
     logger.info("Found NCL version %s", version)
@@ -383,7 +383,7 @@ def _check_duration_periods(timerange):
                 f"{timerange[0]} is not valid duration according to ISO 8601."
                 + "\n"
                 + str(exc)
-            )
+            ) from exc
     elif timerange[1].startswith("P"):
         try:
             isodate.parse_duration(timerange[1])
@@ -393,7 +393,7 @@ def _check_duration_periods(timerange):
                 f"{timerange[1]} is not valid duration according to ISO 8601."
                 + "\n"
                 + str(exc)
-            )
+            ) from exc
 
 
 def _check_format_years(date):
@@ -423,7 +423,7 @@ def _check_timerange_values(date, timerange):
             "for dates and duration periods, or be "
             "set to '*' to load available years. "
             f"Got {timerange} instead." + "\n" + str(exc)
-        )
+        ) from exc
 
 
 def valid_time_selection(timerange):
@@ -584,7 +584,7 @@ def _check_regular_stat(step, step_settings):
     try:
         get_iris_aggregator(operator, **operator_kwargs)
     except ValueError as exc:
-        raise RecipeError(f"Invalid options for {step}: {exc}")
+        raise RecipeError(f"Invalid options for {step}: {exc}") from exc
 
 
 def _check_mm_stat(step, step_settings):
@@ -594,11 +594,11 @@ def _check_mm_stat(step, step_settings):
         try:
             (operator, kwargs) = _get_operator_and_kwargs(stat)
         except ValueError as exc:
-            raise RecipeError(str(exc))
+            raise RecipeError(str(exc)) from exc
         try:
             get_iris_aggregator(operator, **kwargs)
         except ValueError as exc:
-            raise RecipeError(f"Invalid options for {step}: {exc}")
+            raise RecipeError(f"Invalid options for {step}: {exc}") from exc
 
 
 def regridding_schemes(settings: dict):
@@ -645,4 +645,4 @@ def regridding_schemes(settings: dict):
                 f"https://docs.esmvaltool.org/projects/ESMValCore/en/latest"
                 f"/recipe/preprocessor.html#generic-regridding-schemes for "
                 f"details."
-            )
+            ) from exc

esmvalcore/_recipe/recipe.py

@@ -418,11 +418,11 @@ def _update_multiproduct(input_products, order, preproc_dir, step):
     called from the input products, the products that are created here need to
     be added to their ancestors products' settings ().
     """
-    products = {p for p in input_products if step in p.settings}
-    if not products:
+    multiproducts = {p for p in input_products if step in p.settings}
+    if not multiproducts:
         return input_products, {}
 
-    settings = list(products)[0].settings[step]
+    settings = list(multiproducts)[0].settings[step]
 
     if step == "ensemble_statistics":
         check.ensemble_statistics_preproc(settings)
@@ -431,14 +431,16 @@ def _update_multiproduct(input_products, order, preproc_dir, step):
         check.multimodel_statistics_preproc(settings)
         grouping = settings.get("groupby", None)
 
-    downstream_settings = _get_downstream_settings(step, order, products)
+    downstream_settings = _get_downstream_settings(step, order, multiproducts)
 
     relevant_settings = {
         "output_products": defaultdict(dict)
     }  # pass to ancestors
 
     output_products = set()
-    for identifier, products in _group_products(products, by_key=grouping):
+    for identifier, products in _group_products(
+        multiproducts, by_key=grouping
+    ):
         common_attributes = _get_common_attributes(products, settings)
 
         statistics = settings.get("statistics", [])

esmvalcore/cmor/_fixes/fix.py

@@ -141,7 +141,7 @@ def get_cube_from_list(
 
         Raises
         ------
-        Exception
+        ValueError
             No cube is found.
 
         Returns
@@ -155,7 +155,7 @@ def get_cube_from_list(
         for cube in cubes:
             if cube.var_name == short_name:
                 return cube
-        raise Exception(f'Cube for variable "{short_name}" not found')
+        raise ValueError(f'Cube for variable "{short_name}" not found')
 
     def fix_data(self, cube: Cube) -> Cube:
         """Apply fixes to the data of the cube.

esmvalcore/config/_config_object.py

@@ -92,7 +92,7 @@ def __init__(self, *args, **kwargs):
             "Do not instantiate `Config` objects directly, this will lead "
             "to unexpected behavior. Use `esmvalcore.config.CFG` instead."
         )
-        warnings.warn(msg, UserWarning)
+        warnings.warn(msg, UserWarning, stacklevel=2)
 
     # TODO: remove in v2.14.0
     @classmethod
@@ -313,7 +313,7 @@ def load_from_file(
             "ESMValCore version 2.12.0 and is scheduled for removal in "
             "version 2.14.0. Please use `CFG.load_from_dirs()` instead."
         )
-        warnings.warn(msg, ESMValCoreDeprecationWarning)
+        warnings.warn(msg, ESMValCoreDeprecationWarning, stacklevel=2)
         self.clear()
         self.update(Config._load_user_config(filename))
 
@@ -399,7 +399,9 @@ def reload(self) -> None:
                 f"alternatively use a custom `--config_dir`) and omit "
                 f"`--config_file`."
             )
-            warnings.warn(deprecation_msg, ESMValCoreDeprecationWarning)
+            warnings.warn(
+                deprecation_msg, ESMValCoreDeprecationWarning, stacklevel=2
+            )
             self.update(Config._load_user_config(raise_exception=False))
             return
 
@@ -505,7 +507,7 @@ def __init__(self, config: dict, name: str = "session"):
             "to unexpected behavior. Use "
             "`esmvalcore.config.CFG.start_session` instead."
         )
-        warnings.warn(msg, UserWarning)
+        warnings.warn(msg, UserWarning, stacklevel=2)
 
     def set_session_name(self, name: str = "session"):
         """Set the name for the session.
@@ -556,7 +558,7 @@ def config_dir(self):
             "ESMValCore version 2.12.0 and is scheduled for removal in "
             "version 2.14.0."
         )
-        warnings.warn(msg, ESMValCoreDeprecationWarning)
+        warnings.warn(msg, ESMValCoreDeprecationWarning, stacklevel=2)
         if self.get("config_file") is None:
             return None
         return Path(self["config_file"]).parent

esmvalcore/config/_config_validators.py

@@ -311,7 +311,7 @@ def validate_extra_facets_dir(value):
             "ESMValCore version 2.12.0 and is scheduled for removal in "
             "version 2.14.0. Please use a list instead."
         )
-        warnings.warn(msg, ESMValCoreDeprecationWarning)
+        warnings.warn(msg, ESMValCoreDeprecationWarning, stacklevel=2)
         value = list(value)
     return validate_pathlist(value)
 
@@ -371,7 +371,7 @@ def _handle_deprecation(
         f"been deprecated in ESMValCore version {deprecated_version} and is "
         f"scheduled for removal in version {remove_version}.{more_info}"
     )
-    warnings.warn(deprecation_msg, ESMValCoreDeprecationWarning)
+    warnings.warn(deprecation_msg, ESMValCoreDeprecationWarning, stacklevel=2)
 
 
 # TODO: remove in v2.14.0

esmvalcore/config/_validated_config.py

@@ -121,6 +121,7 @@ def check_missing(self):
                 warnings.warn(
                     f"`{key}` is not defined{more_info}",
                     MissingConfigParameter,
+                    stacklevel=1,
                 )
 
     def copy(self):

esmvalcore/experimental/_warnings.py

@@ -14,4 +14,5 @@ def _warning_formatter(message, category, filename, lineno, line=None):
     "\n  Thank you for trying out the new ESMValCore API."
     "\n  Note that this API is experimental and may be subject to change."
     "\n  More info: https://github.com/ESMValGroup/ESMValCore/issues/498",
+    stacklevel=1,
 )

esmvalcore/preprocessor/__init__.py

@@ -717,13 +717,13 @@ def _run(self, _):
                         if step in product.settings:
                             product.apply(step, self.debug)
                     if block == blocks[-1]:
-                        product.cubes  # pylint: disable=pointless-statement
+                        product.cubes  # noqa: B018 pylint: disable=pointless-statement
                         product.close()
                         saved.add(product.filename)
 
         for product in self.products:
             if product.filename not in saved:
-                product.cubes  # pylint: disable=pointless-statement
+                product.cubes  # noqa: B018 pylint: disable=pointless-statement
                 product.close()
 
         metadata_files = write_metadata(

esmvalcore/preprocessor/_derive/__init__.py

@@ -27,7 +27,7 @@ def _get_all_derived_variables():
         module = importlib.import_module(
             f"esmvalcore.preprocessor._derive.{short_name}"
         )
-        derivers[short_name] = getattr(module, "DerivedVariable")
+        derivers[short_name] = module.DerivedVariable
     return derivers
 
 

esmvalcore/preprocessor/_derive/ctotal.py

@@ -37,12 +37,12 @@ def calculate(cubes):
                 c_soil_cube = cubes.extract_cube(
                     Constraint(name="soil_mass_content_of_carbon")
                 )
-            except iris.exceptions.ConstraintMismatchError:
+            except iris.exceptions.ConstraintMismatchError as exc:
                 raise ValueError(
                     f"No cube from {cubes} can be loaded with "
                     f"standard name CMIP5: soil_carbon_content "
                     f"or CMIP6: soil_mass_content_of_carbon"
-                )
+                ) from exc
         c_veg_cube = cubes.extract_cube(
             Constraint(name="vegetation_carbon_content")
         )

esmvalcore/preprocessor/_derive/ohc.py

@@ -74,7 +74,7 @@ def calculate(cubes):
                     contains_dimension=t_coord_dim, dim_coords=False
                 )
             ]
-            for coord, dims in dim_coords + aux_coords:
+            for coord, _ in dim_coords + aux_coords:
                 cube.remove_coord(coord)
         new_cube = cube * volume
         new_cube *= RHO_CP

esmvalcore/preprocessor/_io.py

@@ -321,7 +321,7 @@ def _sort_cubes_by_time(cubes):
         msg = "One or more cubes {} are missing".format(
             cubes
         ) + " time coordinate: {}".format(str(exc))
-        raise ValueError(msg)
+        raise ValueError(msg) from exc
     except TypeError as error:
         msg = (
             "Cubes cannot be sorted "

esmvalcore/preprocessor/_mapping.py

@@ -57,10 +57,10 @@ def ref_to_dims_index_as_index(cube, ref):
     """Get dim for index ref."""
     try:
         dim = int(ref)
-    except (ValueError, TypeError):
+    except (ValueError, TypeError) as exc:
         raise ValueError(
             "{} Incompatible type {} for slicing".format(ref, type(ref))
-        )
+        ) from exc
     if dim < 0 or dim > cube.ndim:
         msg = (
             "Requested an iterator over a dimension ({}) "

esmvalcore/preprocessor/_regrid.py

@@ -588,7 +588,7 @@ def _load_scheme(src_cube: Cube, tgt_cube: Cube, scheme: str | dict):
             "version 2.11.0, ESMValCore is able to determine the most "
             "suitable regridding scheme based on the input data."
         )
-        warnings.warn(msg, ESMValCoreDeprecationWarning)
+        warnings.warn(msg, ESMValCoreDeprecationWarning, stacklevel=2)
         scheme = "nearest"
 
     if scheme == "linear_extrapolate":
@@ -601,7 +601,7 @@ def _load_scheme(src_cube: Cube, tgt_cube: Cube, scheme: str | dict):
             "latest/recipe/preprocessor.html#generic-regridding-schemes)."
             "This is an exact replacement."
         )
-        warnings.warn(msg, ESMValCoreDeprecationWarning)
+        warnings.warn(msg, ESMValCoreDeprecationWarning, stacklevel=2)
         scheme = "linear"
         loaded_scheme = Linear(extrapolation_mode="extrapolate")
         logger.debug("Loaded regridding scheme %s", loaded_scheme)

esmvalcore/preprocessor/_regrid_esmpy.py

@@ -8,7 +8,7 @@
     try:
         import ESMF as esmpy  # noqa: N811
     except ImportError:
-        raise exc
+        raise exc from None
 import warnings
 
 import iris
@@ -78,8 +78,8 @@ def __init__(
     ):
         """Initialize class instance."""
         # These regridders are not lazy, so load source and target data once.
-        src_cube.data  # pylint: disable=pointless-statement
-        tgt_cube.data  # pylint: disable=pointless-statement
+        src_cube.data  # # noqa: B018 pylint: disable=pointless-statement
+        tgt_cube.data  # # noqa: B018 pylint: disable=pointless-statement
         self.src_cube = src_cube
         self.tgt_cube = tgt_cube
         self.method = method
@@ -100,7 +100,7 @@ def __call__(self, cube: Cube) -> Cube:
 
         """
         # These regridders are not lazy, so load source data once.
-        cube.data  # pylint: disable=pointless-statement
+        cube.data  # # noqa: B018 pylint: disable=pointless-statement
         src_rep, dst_rep = get_grid_representants(cube, self.tgt_cube)
         regridder = build_regridder(
             src_rep, dst_rep, self.method, mask_threshold=self.mask_threshold
@@ -140,7 +140,7 @@ def __init__(self, mask_threshold: float = 0.99):
             "`esmvalcore.preprocessor.regrid_schemes.IrisESMFRegrid` "
             "instead."
         )
-        warnings.warn(msg, ESMValCoreDeprecationWarning)
+        warnings.warn(msg, ESMValCoreDeprecationWarning, stacklevel=2)
         self.mask_threshold = mask_threshold
 
     def __repr__(self) -> str:

esmvalcore/preprocessor/_shared.py

@@ -95,7 +95,7 @@ def get_iris_aggregator(
     except (ValueError, TypeError) as exc:
         raise ValueError(
             f"Invalid kwargs for operator '{operator}': {str(exc)}"
-        )
+        ) from exc
 
     return (aggregator, aggregator_kwargs)
 

pyproject.toml

@@ -33,6 +33,7 @@ disable = [
 line-length = 79
 [tool.ruff.lint]
 select = [
+    "B",
     "E",       # pycodestyle
     "F",       # pyflakes
     "I",       # isort
@@ -42,5 +43,9 @@ select = [
 ignore = [
     "E501",  # Disable line-too-long as this is taken care of by the formatter.
 ]
+[tool.ruff.lint.per-file-ignores]
+"tests/**.py" = [
+    "B011",  # `assert False` is valid test code.
+]
 [tool.ruff.lint.isort]
 known-first-party = ["esmvalcore"]