Switch from black to ruff format

.github/bump_version.py

@@ -19,9 +19,7 @@ def get_current_version(pyproject_path: Path) -> str:
 
 def infer_bump(changelog_dir: Path) -> str:
     fragments = [
-        f
-        for f in changelog_dir.iterdir()
-        if f.is_file() and f.name != ".gitkeep"
+        f for f in changelog_dir.iterdir() if f.is_file() and f.name != ".gitkeep"
     ]
     if not fragments:
         print("No changelog fragments found", file=sys.stderr)

.github/workflows/code_changes.yaml

@@ -17,10 +17,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
         - uses: actions/checkout@v4
+        - name: Install uv
+          uses: astral-sh/setup-uv@v5
         - name: Check formatting
-          uses: "lgeiger/black-action@master"
-          with:
-              args: ". -l 79 --check"
+          run: uvx ruff format --check .
   Test:
       runs-on: macos-latest
       permissions:

.github/workflows/pr_code_changes.yaml

@@ -19,10 +19,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
         - uses: actions/checkout@v4
+        - name: Install uv
+          uses: astral-sh/setup-uv@v5
         - name: Check formatting
-          uses: "lgeiger/black-action@master"
-          with:
-              args: ". -l 79 --check"
+          run: uvx ruff format --check .
   Test:
       runs-on: macos-latest
       permissions:

CLAUDE.md

@@ -6,14 +6,14 @@
 
 ## Build commands
 - Install: `make install` or `pip install -e ".[dev]" --config-settings editable_mode=compat`
-- Format code: `make format` or `black . -l 79`
+- Format code: `make format` or `ruff format .`
 - Run all tests: `make test`
 - Run single test: `pytest policyengine_uk/tests/path/to/test_file.py::test_function -v`
 - Generate documentation: `make documentation`
 - Update changelog: `make changelog`
 
 ## Code Standards
-- **Formatting**: Use Black with 79-character line length
+- **Formatting**: Use Ruff formatter with 88-character line length
 - **Imports**: Group imports by stdlib, third-party, local with each group alphabetized
 - **Naming**: Use snake_case for variables/functions, CamelCase for classes
 - **Type Hints**: Use Python type hints where possible

Makefile

@@ -11,7 +11,7 @@ install:
 	pip install huggingface_hub
 
 format:
-	black . -l 79
+	ruff format .
 
 test:
 	policyengine-core test policyengine_uk/tests/policy -c policyengine_uk

changelog.d/switch-to-ruff.changed.md

@@ -0,0 +1 @@
+Switch from black to ruff format.

docs/book/programs/gov/dcms/bbc/tv-licence.ipynb

@@ -128,12 +128,10 @@
     "\n",
     "df = pd.DataFrame()\n",
     "df[\"Date\"] = [\n",
-    "    parameter.instant_str\n",
-    "    for parameter in dcms.bbc.tv_licence.colour.values_list\n",
+    "    parameter.instant_str for parameter in dcms.bbc.tv_licence.colour.values_list\n",
     "]\n",
     "df[\"Full TV Licence Fee\"] = [\n",
-    "    f\"£{parameter.value:.2f}\"\n",
-    "    for parameter in dcms.bbc.tv_licence.colour.values_list\n",
+    "    f\"£{parameter.value:.2f}\" for parameter in dcms.bbc.tv_licence.colour.values_list\n",
     "]\n",
     "df[\"Blind TV Licence Fee\"] = [\n",
     "    f\"£{0.5 * parameter.value:.2f}\"\n",
@@ -334,9 +332,7 @@
     "    aged_discount[\"Change against current\"] += [\n",
     "        f\"{aged_discount['Reformed value'][i] - 1:.0%}\"\n",
     "    ]\n",
-    "    aged_discount[\"Reformed value\"][\n",
-    "        i\n",
-    "    ] = f\"{aged_discount['Reformed value'][i]:.0%}\"\n",
+    "    aged_discount[\"Reformed value\"][i] = f\"{aged_discount['Reformed value'][i]:.0%}\"\n",
     "    aged_discount[\"Reference\"] += [\n",
     "        f'<a href=\"{reference_list_ad[i]}\">Budgetary impact of changing aged discount to {aged_discount[\"Reformed value\"][i]}</a>'\n",
     "    ]\n",

docs/book/programs/gov/dwp/pension-credit.ipynb

@@ -167,12 +167,8 @@
     "\n",
     "parameters = system.parameters\n",
     "\n",
-    "carer_addition = (\n",
-    "    parameters.gov.dwp.pension_credit.guarantee_credit.carer.addition\n",
-    ")\n",
-    "child_addition = (\n",
-    "    parameters.gov.dwp.pension_credit.guarantee_credit.child.addition\n",
-    ")\n",
+    "carer_addition = parameters.gov.dwp.pension_credit.guarantee_credit.carer.addition\n",
+    "child_addition = parameters.gov.dwp.pension_credit.guarantee_credit.child.addition\n",
     "disabled_child = (\n",
     "    parameters.gov.dwp.pension_credit.guarantee_credit.child.disability.addition\n",
     ")\n",
@@ -1506,12 +1502,8 @@
     "\n",
     "parameters = system.parameters\n",
     "\n",
-    "threshold_single = (\n",
-    "    parameters.gov.dwp.pension_credit.savings_credit.threshold.SINGLE\n",
-    ")\n",
-    "threshold_couple = (\n",
-    "    parameters.gov.dwp.pension_credit.savings_credit.threshold.COUPLE\n",
-    ")\n",
+    "threshold_single = parameters.gov.dwp.pension_credit.savings_credit.threshold.SINGLE\n",
+    "threshold_couple = parameters.gov.dwp.pension_credit.savings_credit.threshold.COUPLE\n",
     "\n",
     "elements = [threshold_single, threshold_couple]  # [...]\n",
     "\n",

docs/book/programs/gov/dwp/universal-credit.ipynb

@@ -194,9 +194,7 @@
     "disabled_child_amount = (\n",
     "    parameters.gov.dwp.universal_credit.elements.child.disabled.amount\n",
     ")\n",
-    "higher_amount = (\n",
-    "    parameters.gov.dwp.universal_credit.elements.child.first.higher_amount\n",
-    ")\n",
+    "higher_amount = parameters.gov.dwp.universal_credit.elements.child.first.higher_amount\n",
     "\n",
     "elements = [\n",
     "    carer_amount,\n",

docs/book/programs/gov/hmrc/child-benefit.ipynb

@@ -175,9 +175,7 @@
     "        data[\"Reference\"] += [\"\"]\n",
     "\n",
     "\n",
-    "for (\n",
-    "    parameter\n",
-    ") in parameters.gov.hmrc.child_benefit.amount.additional.values_list:\n",
+    "for parameter in parameters.gov.hmrc.child_benefit.amount.additional.values_list:\n",
     "    data[\"Date\"] += [parameter.instant_str]\n",
     "    data[\"Name\"] += [\"Additional\"]\n",
     "    data[\"Value\"] += [f\"£{parameter.value:.2f}\"]\n",
@@ -189,9 +187,9 @@
     "        data[\"Reference\"] += [\"\"]\n",
     "\n",
     "\n",
-    "pd.DataFrame(data).sort_values(\"Date\").set_index(\n",
-    "    [\"Date\", \"Name\"]\n",
-    ").style.format(lambda x: x)"
+    "pd.DataFrame(data).sort_values(\"Date\").set_index([\"Date\", \"Name\"]).style.format(\n",
+    "    lambda x: x\n",
+    ")"
    ]
   },
   {
@@ -302,9 +300,7 @@
     "pd.DataFrame(\n",
     "    {\n",
     "        \"Number of children\": list(range(1, 7)),\n",
-    "        \"Child Benefit (Annual)\": list(\n",
-    "            map(get_cb_for_n_children, range(1, 7))\n",
-    "        ),\n",
+    "        \"Child Benefit (Annual)\": list(map(get_cb_for_n_children, range(1, 7))),\n",
     "    }\n",
     ").set_index(\"Number of children\")"
    ]

docs/book/programs/gov/hmrc/fuel-duty.ipynb

@@ -126,12 +126,10 @@
     "df = pd.DataFrame()\n",
     "\n",
     "df[\"Date of change\"] = [\n",
-    "    parameter.instant_str\n",
-    "    for parameter in hmrc.fuel_duty.petrol_and_diesel.values_list\n",
+    "    parameter.instant_str for parameter in hmrc.fuel_duty.petrol_and_diesel.values_list\n",
     "]\n",
     "df[\"Fuel duty rate (£/litre)\"] = [\n",
-    "    parameter.value\n",
-    "    for parameter in hmrc.fuel_duty.petrol_and_diesel.values_list\n",
+    "    parameter.value for parameter in hmrc.fuel_duty.petrol_and_diesel.values_list\n",
     "]\n",
     "df.sort_values(\"Date of change\", inplace=True)\n",
     "df.set_index(\"Date of change\")"
@@ -1072,11 +1070,7 @@
     "    height=600,\n",
     "    width=800,\n",
     "    template=\"plotly_white\",\n",
-    ").update_xaxes(\n",
-    "    tickangle=45, tickfont={\"size\": 10}\n",
-    ").update_traces(\n",
-    "    line_shape=\"hv\"\n",
-    ")"
+    ").update_xaxes(tickangle=45, tickfont={\"size\": 10}).update_traces(line_shape=\"hv\")"
    ]
   }
  ],

docs/book/programs/gov/hmrc/income-tax.ipynb

@@ -207,9 +207,7 @@
     "from policyengine_uk import Simulation\n",
     "\n",
     "\n",
-    "def calculate_taxes(\n",
-    "    employment_income, dividend_income, savings_interest_income\n",
-    "):\n",
+    "def calculate_taxes(employment_income, dividend_income, savings_interest_income):\n",
     "    simulation = Simulation(\n",
     "        situation={\n",
     "            \"people\": {\n",
@@ -222,9 +220,7 @@
     "        }\n",
     "    )\n",
     "    income_tax = simulation.calculate(\"income_tax\")[0]\n",
-    "    dividend_income_tax = simulation.calculate(\"dividend_income_tax\")[\n",
-    "        0\n",
-    "    ]  # Added\n",
+    "    dividend_income_tax = simulation.calculate(\"dividend_income_tax\")[0]  # Added\n",
     "    savings_income_tax = simulation.calculate(\"savings_income_tax\")[0]  # Added\n",
     "\n",
     "    return income_tax, dividend_income_tax, savings_income_tax\n",
@@ -245,9 +241,7 @@
     "    data[\"Dividend Income (£)\"],\n",
     "    data[\"Savings Interest Income (£)\"],\n",
     "):\n",
-    "    income_tax, div_tax, sav_tax = calculate_taxes(\n",
-    "        emp_income, div_income, sav_income\n",
-    "    )\n",
+    "    income_tax, div_tax, sav_tax = calculate_taxes(emp_income, div_income, sav_income)\n",
     "    data[\"Income Tax (£)\"].append(income_tax)\n",
     "    data[\"Dividend Income Tax (£)\"].append(div_tax)\n",
     "    data[\"Savings Income Tax (£)\"].append(sav_tax)\n",
@@ -524,12 +518,8 @@
     "from policyengine_uk.system import system\n",
     "import pandas as pd\n",
     "\n",
-    "default = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.annual_allowance.default\n",
-    ")\n",
-    "minimum = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.annual_allowance.minimum\n",
-    ")\n",
+    "default = system.parameters.gov.hmrc.income_tax.allowances.annual_allowance.default\n",
+    "minimum = system.parameters.gov.hmrc.income_tax.allowances.annual_allowance.minimum\n",
     "reduction_rate = (\n",
     "    system.parameters.gov.hmrc.income_tax.allowances.annual_allowance.reduction_rate\n",
     ")\n",
@@ -559,9 +549,7 @@
     "\n",
     "\n",
     "max = system.parameters.gov.hmrc.income_tax.allowances.marriage_allowance.max\n",
-    "rounding_increment = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.marriage_allowance.rounding_increment\n",
-    ")\n",
+    "rounding_increment = system.parameters.gov.hmrc.income_tax.allowances.marriage_allowance.rounding_increment\n",
     "takeup_rate = (\n",
     "    system.parameters.gov.hmrc.income_tax.allowances.marriage_allowance.takeup_rate\n",
     ")\n",
@@ -586,9 +574,7 @@
     "}\n",
     "\n",
     "\n",
-    "deduction_rate = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.married_couples_allowance.deduction_rate\n",
-    ")\n",
+    "deduction_rate = system.parameters.gov.hmrc.income_tax.allowances.married_couples_allowance.deduction_rate\n",
     "married_couples_allowance_data = {\n",
     "    \"Attribute\": [\"Married Couples Allowance\"],\n",
     "    \"Type\": [\"Deduction Rate\"],\n",
@@ -598,9 +584,7 @@
     "}\n",
     "\n",
     "\n",
-    "amount = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.personal_allowance.amount\n",
-    ")\n",
+    "amount = system.parameters.gov.hmrc.income_tax.allowances.personal_allowance.amount\n",
     "values = [item.value for item in amount.values_list]\n",
     "dates = [item.instant_str for item in amount.values_list]\n",
     "personal_allowance_data = {\n",
@@ -612,9 +596,7 @@
     "}\n",
     "\n",
     "\n",
-    "addtional_threshold = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.personal_savings_allowance.additional\n",
-    ")\n",
+    "addtional_threshold = system.parameters.gov.hmrc.income_tax.allowances.personal_savings_allowance.additional\n",
     "basic_threshold = (\n",
     "    system.parameters.gov.hmrc.income_tax.allowances.personal_savings_allowance.basic\n",
     ")\n",
@@ -642,9 +624,7 @@
     "}\n",
     "\n",
     "\n",
-    "dividend_allowance = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.dividend_allowance\n",
-    ")\n",
+    "dividend_allowance = system.parameters.gov.hmrc.income_tax.allowances.dividend_allowance\n",
     "dividend_allowance_data = {\n",
     "    \"Attribute\": [\"Dividend Allowance\"],\n",
     "    \"Type\": [\"Dividend Allowance\"],\n",
@@ -654,9 +634,7 @@
     "}\n",
     "\n",
     "\n",
-    "property_allowance = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.property_allowance\n",
-    ")\n",
+    "property_allowance = system.parameters.gov.hmrc.income_tax.allowances.property_allowance\n",
     "property_allowance_data = {\n",
     "    \"Attribute\": [\"Property Allowance\"],\n",
     "    \"Type\": [\"Property Allowance\"],\n",
@@ -666,9 +644,7 @@
     "}\n",
     "\n",
     "\n",
-    "trading_allowance = (\n",
-    "    system.parameters.gov.hmrc.income_tax.allowances.trading_allowance\n",
-    ")\n",
+    "trading_allowance = system.parameters.gov.hmrc.income_tax.allowances.trading_allowance\n",
     "trading_allowance_data = {\n",
     "    \"Attribute\": [\"Trading Allowance\"],\n",
     "    \"Type\": [\"Trading Allowance\"],\n",

docs/book/programs/gov/hmrc/stamp-duty.ipynb

@@ -6287,9 +6287,7 @@
     "stamp_duty = sim.calculate(\"stamp_duty_land_tax\")\n",
     "home_price = sim.calculate(\"main_residential_property_purchased\")\n",
     "\n",
-    "marginal_rate = (stamp_duty[1:] - stamp_duty[:-1]) / (\n",
-    "    home_price[1:] - home_price[:-1]\n",
-    ")\n",
+    "marginal_rate = (stamp_duty[1:] - stamp_duty[:-1]) / (home_price[1:] - home_price[:-1])\n",
     "home_price = home_price[:-1]\n",
     "\n",
     "df = pd.DataFrame(\n",
@@ -6305,14 +6303,10 @@
     "\n",
     "# left shows marginal rate, right shows total SDLT\n",
     "\n",
-    "fig = make_subplots(\n",
-    "    rows=1, cols=2, subplot_titles=(\"Marginal SDLT rate\", \"Total SDLT\")\n",
-    ")\n",
+    "fig = make_subplots(rows=1, cols=2, subplot_titles=(\"Marginal SDLT rate\", \"Total SDLT\"))\n",
     "\n",
     "fig.add_trace(\n",
-    "    px.line(\n",
-    "        df, x=\"Home price\", y=\"Marginal SDLT rate\", title=\"Marginal SDLT rate\"\n",
-    "    )\n",
+    "    px.line(df, x=\"Home price\", y=\"Marginal SDLT rate\", title=\"Marginal SDLT rate\")\n",
     "    .update_traces(line_shape=\"hv\")\n",
     "    .data[0],\n",
     "    row=1,\n",

docs/book/programs/gov/ofgem/energy-price-guarantee.ipynb

@@ -1011,9 +1011,7 @@
     "\n",
     "df = pd.DataFrame()\n",
     "\n",
-    "df[\"Date\"] = [\n",
-    "    parameter.instant_str for parameter in ofgem.energy_price_cap.values_list\n",
-    "]\n",
+    "df[\"Date\"] = [parameter.instant_str for parameter in ofgem.energy_price_cap.values_list]\n",
     "df[\"Energy price cap\"] = [\n",
     "    parameter.value for parameter in ofgem.energy_price_cap.values_list\n",
     "]\n",
@@ -1107,9 +1105,9 @@
          "xaxis": "x",
          "y": [
           8.373929949593731e-10,
-          1.674785989918746e-09,
-          2.512178984878119e-09,
-          3.3495719798374923e-09,
+          1.674785989918746e-9,
+          2.512178984878119e-9,
+          3.3495719798374923e-9,
           1.2009600411861108,
           2.40192007902265,
           3.602880116859188,
@@ -1998,9 +1996,7 @@
     "    *[f\"2023-{month:02d}\" for month in range(1, 13)],\n",
     "]\n",
     "\n",
-    "epg_costs = [\n",
-    "    sim.calc(\"monthly_epg_subsidy\", period).sum() for period in time_periods\n",
-    "]\n",
+    "epg_costs = [sim.calc(\"monthly_epg_subsidy\", period).sum() for period in time_periods]\n",
     "\n",
     "df = pd.DataFrame(\n",
     "    {\n",