use ruff as linter

.github/workflows/lint.yml

@@ -5,7 +5,7 @@ on: [push, pull_request]
 jobs:
  build:
  runs-on: ubuntu-latest
- name: black-flake8-mypy
+ name: black-ruff-mypy
  steps:
  - uses: actions/checkout@v3
  - name: Set up Python 3.10
@@ -21,9 +21,10 @@ jobs:
  run: |
  black --diff --color .
  black --check .
- - name: Lint with flake8
- run: |
- flake8 . --statistics
+ - name: Lint with ruff
+ run: | 
+ ruff check .
+
  - name: Lint with mypy
  run: |
  mypy altair tests

Makefile

@@ -5,7 +5,7 @@ install:
 
 test :
  black --diff --color --check .
- flake8 . --statistics
+ ruff check .
  mypy altair tests
  python -m pytest --pyargs --doctest-modules tests
 

altair/__init__.py

@@ -1,4 +1,4 @@
-# flake8: noqa
+# ruff: noqa
 __version__ = "5.0.0dev"
 
 from typing import Any

altair/_magics.py

@@ -44,7 +44,7 @@ def _prepare_data(data, data_transformers):
  elif isinstance(data, str):
  return {"url": data}
  else:
- warnings.warn("data of type {} not recognized".format(type(data)))
+ warnings.warn("data of type {} not recognized".format(type(data)), stacklevel=1)
  return data
 
 
@@ -94,11 +94,11 @@ def vegalite(line, cell):
  elif not YAML_AVAILABLE:
  try:
  spec = json.loads(cell)
- except json.JSONDecodeError:
+ except json.JSONDecodeError as err:
  raise ValueError(
  "%%vegalite: spec is not valid JSON. "
  "Install pyyaml to parse spec as yaml"
- )
+ ) from err
  else:
  spec = yaml.load(cell, Loader=yaml.SafeLoader)
 

altair/expr/__init__.py

@@ -1,5 +1,5 @@
 """Tools for creating transform & filter expressions with a python syntax"""
-# flake8: noqa
+# ruff: noqa
 from typing import Any
 
 from .core import datum, Expression

altair/utils/core.py

@@ -227,7 +227,8 @@ def infer_vegalite_type(data):
  else:
  warnings.warn(
  "I don't know how to infer vegalite type from '{}'. "
- "Defaulting to nominal.".format(typ)
+ "Defaulting to nominal.".format(typ),
+ stacklevel=1,
  )
  return "nominal"
 
@@ -483,15 +484,15 @@ def parse_shorthand(
 
  valid_typecodes = list(TYPECODE_MAP) + list(INV_TYPECODE_MAP)
 
- units = dict(
- field="(?P<field>.*)",
- type="(?P<type>{})".format("|".join(valid_typecodes)),
- agg_count="(?P<aggregate>count)",
- op_count="(?P<op>count)",
- aggregate="(?P<aggregate>{})".format("|".join(AGGREGATES)),
- window_op="(?P<op>{})".format("|".join(AGGREGATES + WINDOW_AGGREGATES)),
- timeUnit="(?P<timeUnit>{})".format("|".join(TIMEUNITS)),
- )
+ units = {
+ "field": "(?P<field>.*)",
+ "type": "(?P<type>{})".format("|".join(valid_typecodes)),
+ "agg_count": "(?P<aggregate>count)",
+ "op_count": "(?P<op>count)",
+ "aggregate": "(?P<aggregate>{})".format("|".join(AGGREGATES)),
+ "window_op": "(?P<op>{})".format("|".join(AGGREGATES + WINDOW_AGGREGATES)),
+ "timeUnit": "(?P<timeUnit>{})".format("|".join(TIMEUNITS)),
+ }
 
  patterns = []
 
@@ -710,7 +711,9 @@ def _wrap_in_channel_class(obj, encoding):
  return [_wrap_in_channel_class(subobj, encoding) for subobj in obj]
 
  if encoding not in name_to_channel:
- warnings.warn("Unrecognized encoding channel '{}'".format(encoding))
+ warnings.warn(
+ "Unrecognized encoding channel '{}'".format(encoding), stacklevel=1
+ )
  return obj
 
  classes = name_to_channel[encoding]

altair/utils/data.py

@@ -258,6 +258,7 @@ def pipe(data, *funcs):
  "alt.pipe() is deprecated, and will be removed in a future release. "
  "Use toolz.curried.pipe() instead.",
  AltairDeprecationWarning,
+ stacklevel=1,
  )
  return curried.pipe(data, *funcs)
 
@@ -271,6 +272,7 @@ def curry(*args, **kwargs):
  "alt.curry() is deprecated, and will be removed in a future release. "
  "Use toolz.curried.curry() instead.",
  AltairDeprecationWarning,
+ stacklevel=1,
  )
  return curried.curry(*args, **kwargs)
 
@@ -284,14 +286,14 @@ def import_pyarrow_interchange():
  import pyarrow.interchange as pi
 
  return pi
- except pkg_resources.DistributionNotFound:
+ except pkg_resources.DistributionNotFound as err:
  # The package is not installed
  raise ImportError(
  "Usage of the DataFrame Interchange Protocol requires the package 'pyarrow', but it is not installed."
- )
- except pkg_resources.VersionConflict:
+ ) from err
+ except pkg_resources.VersionConflict as err:
  # The package is installed but does not meet the minimum version requirement
  raise ImportError(
  "The installed version of 'pyarrow' does not meet the minimum requirement of version 11.0.0. "
  "Please update 'pyarrow' to use the DataFrame Interchange Protocol."
- )
+ ) from err

altair/utils/deprecation.py

@@ -62,7 +62,7 @@ def _deprecate(obj, name=None, message=None):
 
  @functools.wraps(obj)
  def new_obj(*args, **kwargs):
- warnings.warn(message, AltairDeprecationWarning)
+ warnings.warn(message, AltairDeprecationWarning, stacklevel=1)
  return obj(*args, **kwargs)
 
  new_obj._deprecated = True

altair/utils/html.py

@@ -251,14 +251,14 @@ def spec_to_html(
  if mode == "vega-lite" and vegalite_version is None:
  raise ValueError("must specify vega-lite version for mode='vega-lite'")
 
- render_kwargs = dict()
+ render_kwargs = {}
  if template == "inline":
  try:
  from altair_viewer import get_bundled_script
- except ImportError:
+ except ImportError as err:
  raise ImportError(
  "The altair_viewer package is required to convert to HTML with inline=True"
- )
+ ) from err
  render_kwargs["vega_script"] = get_bundled_script("vega", vega_version)
  render_kwargs["vegalite_script"] = get_bundled_script(
  "vega-lite", vegalite_version

altair/utils/plugin_registry.py

@@ -157,11 +157,11 @@ def _enable(self, name: str, **options) -> None:
  for ep in importlib_metadata_get(self.entry_point_group)
  if ep.name == name
  ]
- except ValueError:
+ except ValueError as err:
  if name in self.entrypoint_err_messages:
- raise ValueError(self.entrypoint_err_messages[name])
+ raise ValueError(self.entrypoint_err_messages[name]) from err
  else:
- raise NoSuchEntryPoint(self.entry_point_group, name)
+ raise NoSuchEntryPoint(self.entry_point_group, name) from err
  value = cast(PluginType, ep.load())
  self.register(name, value)
  self._active_name = name

altair/utils/save.py

@@ -30,7 +30,7 @@ def set_inspect_format_argument(format, fp, inline):
  )
 
  if format != "html" and inline:
- warnings.warn("inline argument ignored for non HTML formats.")
+ warnings.warn("inline argument ignored for non HTML formats.", stacklevel=1)
 
  return format
 

altair/utils/schemapi.py

@@ -564,11 +564,22 @@ def to_dict(self, validate=True, ignore=None, context=None):
  try:
  self.validate(result)
  except jsonschema.ValidationError as err:
- raise SchemaValidationError(self, err)
+ # We do not raise `from err` as else the resulting
+ # traceback is very long as it contains part
+ # of the Vega-Lite schema. It would also first
+ # show the less helpful ValidationError instead of
+ # the more user friendly SchemaValidationError
+ raise SchemaValidationError(self, err) from None
  return result
 
  def to_json(
- self, validate=True, ignore=[], context={}, indent=2, sort_keys=True, **kwargs
+ self,
+ validate=True,
+ ignore=None,
+ context=None,
+ indent=2,
+ sort_keys=True,
+ **kwargs,
  ):
  """Emit the JSON representation for this object as a string.
 
@@ -577,7 +588,7 @@ def to_json(
  validate : boolean
  If True (default), then validate the output dictionary
  against the schema.
- ignore : list
+ ignore : list (optional)
  A list of keys to ignore. This will *not* passed to child to_dict
  function calls.
  context : dict (optional)
@@ -595,6 +606,10 @@ def to_json(
  spec : string
  The JSON specification of the chart object.
  """
+ if ignore is None:
+ ignore = []
+ if context is None:
+ context = {}
  dct = self.to_dict(validate=validate, ignore=ignore, context=context)
  return json.dumps(dct, indent=indent, sort_keys=sort_keys, **kwargs)
 

altair/vegalite/__init__.py

@@ -1,2 +1,2 @@
-# flake8: noqa
+# ruff: noqa
 from .v5 import *

altair/vegalite/api.py

@@ -1,2 +1,2 @@
-# flake8: noqa
+# ruff: noqa
 from .v5.api import *

altair/vegalite/schema.py

@@ -1,3 +1,3 @@
 """Altair schema wrappers"""
-# flake8: noqa
+# ruff: noqa
 from .v5.schema import *

altair/vegalite/v5/__init__.py

@@ -1,4 +1,4 @@
-# flake8: noqa
+# ruff: noqa
 from .schema import *
 from .api import *
 

altair/vegalite/v5/api.py

@@ -112,7 +112,7 @@ def _prepare_data(data, context=None):
 
  # if data is still not a recognized type, then return
  if not isinstance(data, (dict, core.Data)):
- warnings.warn("data of type {} not recognized".format(type(data)))
+ warnings.warn("data of type {} not recognized".format(type(data)), stacklevel=1)
 
  return data
 
@@ -355,12 +355,14 @@ def param(
  warnings.warn(
  """The value of 'empty' should be True or False.""",
  utils.AltairDeprecationWarning,
+ stacklevel=1,
  )
  parameter.empty = False
  elif parameter.empty == "all":
  warnings.warn(
  """The value of 'empty' should be True or False.""",
  utils.AltairDeprecationWarning,
+ stacklevel=1,
  )
  parameter.empty = True
  elif (parameter.empty is False) or (parameter.empty is True):
@@ -372,6 +374,7 @@ def param(
  warnings.warn(
  """Use 'value' instead of 'init'.""",
  utils.AltairDeprecationWarning,
+ stacklevel=1,
  )
  if value is Undefined:
  kwds["value"] = kwds.pop("init")
@@ -416,6 +419,7 @@ def _selection(type=Undefined, **kwds):
  """The types 'single' and 'multi' are now
  combined and should be specified using "selection_point()".""",
  utils.AltairDeprecationWarning,
+ stacklevel=1,
  )
  else:
  raise ValueError("""'type' must be 'point' or 'interval'""")
@@ -2261,11 +2265,11 @@ def show(self, embed_opt=None, open_browser=None):
  """
  try:
  import altair_viewer # type: ignore
- except ImportError:
+ except ImportError as err:
  raise ValueError(
  "'show' method requires the altair_viewer package. "
  "See http://github.com/altair-viz/altair_viewer"
- )
+ ) from err
  altair_viewer.show(self, embed_opt=embed_opt, open_browser=open_browser)
 
  @utils.use_signature(core.Resolve)

altair/vegalite/v5/schema/__init__.py

@@ -1,4 +1,4 @@
-# flake8: noqa
+# ruff: noqa
 from .core import *
 from .channels import *
 SCHEMA_VERSION = 'v5.6.1'

doc/releases/changes.rst

@@ -52,6 +52,11 @@ Backward-Incompatible Changes
 - Removed the Vega-Lite 3 and 4 wrappers (#2847).
 - In regards to the grammar changes listed above, the old terminology will still work in many basic cases. On the other hand, if that old terminology gets used at a lower level, then it most likely will not work. For example, in the current version of :ref:`gallery_scatter_with_minimap`, two instances of the key ``param`` are used in dictionaries to specify axis domains. Those used to be ``selection``, but that usage is not compatible with the current Vega-Lite schema.
 
+Maintenance
+~~~~~~~~~~~
+
+- Vega-Altair now uses ``ruff`` for linting.
+
 Version 4.2.2 (released Jan 27, 2023)
 -------------------------------------
 

pyproject.toml

@@ -22,6 +22,37 @@ exclude = '''
 requires = ["setuptools >= 40.6.0, <64", "wheel"]
 build-backend = "setuptools.build_meta"
 
+[tool.ruff]
+target-version = "py310"
+line-length = 88
+select = [
+ # flake8-bugbear
+ "B",
+ # flake8-comprehensions
+ "C4",
+ # pycodestyle-error
+ "E",
+ # pycodestyle-warning
+ "W",
+ # pyflakes
+ "F",
+ # flake8-tidy-imports
+ "TID"
+]
+# ignore = ["E203", "E266", "E501", "W503"] see https://github.com/charliermarsh/ruff/issues/2402
+ignore = ["E501", "TID252", "B905"]
+exclude = [
+ ".git",
+ "build",
+ "__pycache__",
+ "tests/examples_arguments_syntax",
+ "tests/examples_methods_syntax",
+ "altair/vegalite/v?/schema",
+]
+
+[tool.ruff.mccabe]
+max-complexity = 18
+
 [tool.pytest.ini_options]
 markers = [
  "save_engine: marks some of the tests which are using an external package to save a chart to e.g. a png file. This mark is used to run those tests selectively in the build GitHub Action.",

requirements_dev.txt

@@ -1,6 +1,6 @@
 black<24
 ipython
-flake8
+ruff
 pytest
 pytest-cov
 m2r