Add ruff linting to Makefile format target

Configure ruff check with E (pycodestyle), F (pyflakes), and I (isort)
rule sets. Auto-fixed import sorting; remaining rules that conflict with
existing code patterns are ignored for now. This makes ruff check
available via `make format` without enforcing it in CI yet.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: MaxGhenis

Makefile

@@ -6,6 +6,7 @@ documentation:
 	python docs/add_plotly_to_book.py docs/_build
 
 format:
+	ruff check . --fix
 	ruff format .
 
 install:

changelog.d/add-ruff-linting.added.md

@@ -0,0 +1 @@
+Added ruff linting (ruff check) to Makefile format target with E, F, and I rule sets.

docs/usage/country.ipynb

@@ -16,11 +16,11 @@
    "outputs": [],
    "source": [
     "from policyengine_core.country_template import (\n",
-    "    CountryTaxBenefitSystem,  # Holds all policy-related data.\n",
-    "    Simulation,  # General purpose: enables users to simulate policy on new data.\n",
-    "    Microsimulation,  # Specific purpose: enables users to simulate policy on large datasets.\n",
     "    COUNTRY_DIR,  # Path to the country directory.\n",
     "    DATASETS,  # List of datasets available for this country (to use with `Microsimulation`).\n",
+    "    CountryTaxBenefitSystem,  # Holds all policy-related data.\n",
+    "    Microsimulation,  # Specific purpose: enables users to simulate policy on large datasets.\n",
+    "    Simulation,  # General purpose: enables users to simulate policy on new data.\n",
     ")"
    ]
   },
@@ -52,23 +52,16 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "import os\n",
-    "from typing import Dict, Type\n",
-    "from policyengine_core.data.dataset import Dataset\n",
-    "from policyengine_core.populations.population import Population\n",
-    "from policyengine_core.taxbenefitsystems import TaxBenefitSystem\n",
     "from policyengine_core.country_template import entities\n",
-    "from policyengine_core.country_template.situation_examples import couple\n",
-    "from policyengine_core.simulations import Simulation as CoreSimulation\n",
-    "from policyengine_core.simulations import (\n",
-    "    Microsimulation as CoreMicrosimulation,\n",
-    ")\n",
+    "from policyengine_core.country_template.constants import COUNTRY_DIR\n",
     "from policyengine_core.country_template.data.datasets.country_template_dataset import (\n",
     "    CountryTemplateDataset,\n",
     ")\n",
-    "from pathlib import Path\n",
-    "import logging\n",
-    "from policyengine_core.country_template.constants import COUNTRY_DIR\n",
+    "from policyengine_core.simulations import (\n",
+    "    Microsimulation as CoreMicrosimulation,\n",
+    ")\n",
+    "from policyengine_core.simulations import Simulation as CoreSimulation\n",
+    "from policyengine_core.taxbenefitsystems import TaxBenefitSystem\n",
     "\n",
     "DATASETS = [CountryTemplateDataset]  # Important: must be instantiated\n",
     "\n",

docs/usage/datasets.ipynb

@@ -32,7 +32,7 @@
    "source": [
     "from policyengine_core.country_template.constants import COUNTRY_DIR\n",
     "from policyengine_core.data import Dataset\n",
-    "from policyengine_core.periods import ETERNITY, MONTH, period\n",
+    "from policyengine_core.periods import ETERNITY, period\n",
     "\n",
     "\n",
     "class CountryTemplateDataset(Dataset):\n",

docs/usage/simulation.ipynb

@@ -1044,7 +1044,8 @@
    ],
    "source": [
     "import plotly.express as px\n",
-    "from policyengine_core.charts import format_fig, display_fig, BLUE\n",
+    "\n",
+    "from policyengine_core.charts import BLUE, format_fig\n",
     "\n",
     "fig = (\n",
     "    px.line(\n",

policyengine_core/charts/__init__.py

@@ -1,15 +1,14 @@
+from .api import *
+from .bar import *
 from .formatting import (
     BLUE,
     BLUE_COLOUR_SCALE,
-    DARK_GREEN,
-    LIGHT_GREEN,
     DARK_GRAY,
+    DARK_GREEN,
     GRAY,
     LIGHT_GRAY,
+    LIGHT_GREEN,
     WHITE,
-    format_fig,
     display_fig,
+    format_fig,
 )
-
-from .bar import *
-from .api import *

policyengine_core/charts/api.py

@@ -1,12 +1,14 @@
-import requests
 import time
+
 import plotly.graph_objects as go
+import requests
+
 from .formatting import (
+    BLUE_LIGHT,
+    BLUE_PRIMARY,
     DARK_GRAY,
     MEDIUM_DARK_GRAY,
     WHITE,
-    BLUE_LIGHT,
-    BLUE_PRIMARY,
     format_fig,
 )
 

policyengine_core/charts/bar.py

@@ -1,9 +1,11 @@
+from typing import Callable
+
+import numpy as np
 import pandas as pd
-from .formatting import *
 import plotly.express as px
 from microdf import MicroSeries
-from typing import Callable
-import numpy as np
+
+from .formatting import *
 
 
 def bar_chart(

policyengine_core/commons/formulas.py

@@ -1,25 +1,20 @@
 import logging
 from typing import Any, Callable, Dict, List, Sequence, Type, TypeVar, Union
+from warnings import warn
 
 import numpy
 import numpy as np
 import pandas as pd
-from numpy import logical_not as not_
 from numpy import maximum as max_
 from numpy import minimum as min_
-from numpy import round as round_
-from numpy import select, where
-
-from warnings import warn
+from numpy import select
 
 from policyengine_core.parameters.parameter_node import ParameterNode
 from policyengine_core.periods.period_ import Period
 from policyengine_core.populations.population import Population
 from policyengine_core.types import ArrayLike, ArrayType
 from policyengine_core.variables.variable import Variable
 
-import json
-
 T = TypeVar("T")
 
 
@@ -426,7 +421,7 @@ def sum_of_variables(variables: Union[List[str], str]) -> Callable:
     """
 
     warn(
-        f"Sum-of-variables formulas are deprecated- please use `adds` or `subtracts` instead."
+        "Sum-of-variables formulas are deprecated- please use `adds` or `subtracts` instead."
     )
 
     def sum_of_variables(entity, period, parameters):

policyengine_core/country_template/data/datasets/country_template_dataset.py

@@ -1,6 +1,6 @@
 from policyengine_core.country_template.constants import COUNTRY_DIR
 from policyengine_core.data import Dataset
-from policyengine_core.periods import ETERNITY, MONTH, period
+from policyengine_core.periods import ETERNITY, period
 
 
 class CountryTemplateDataset(Dataset):