feat(pygal): implement box-grouped (#5995)

## Implementation: `box-grouped` - python/pygal

Implements the **python/pygal** version of `box-grouped`.

**File:** `plots/box-grouped/implementations/python/pygal.py`

**Parent Issue:** #2017

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/25535051660)*

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

plots/box-grouped/implementations/python/pygal.py

@@ -1,14 +1,23 @@
-""" pyplots.ai
+""" anyplot.ai
 box-grouped: Grouped Box Plot
-Library: pygal 3.1.0 | Python 3.13.11
-Quality: 85/100 | Created: 2025-12-25
+Library: pygal 3.1.0 | Python 3.13.13
+Quality: 85/100 | Updated: 2026-05-08
 """
 
+import os
+
 import numpy as np
 import pygal
 from pygal.style import Style
 
 
+THEME = os.getenv("ANYPLOT_THEME", "light")
+PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
+INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
+INK_MUTED = "#6B6A63" if THEME == "light" else "#A8A79F"
+
+OKABE_ITO = ("#009E73", "#D55E00", "#0072B2", "#CC79A7", "#E69F00", "#56B4E9", "#F0E442")
+
 # Data - Employee performance scores across departments and experience levels
 np.random.seed(42)
 
@@ -37,36 +46,34 @@
 data[("Sales", "Senior")] = np.append(data[("Sales", "Senior")], [40, 105])
 data[("Marketing", "Lead")] = np.append(data[("Marketing", "Lead")], [60, 100])
 
-# Subcategory colors (colorblind-safe: blue, orange, teal)
-subcategory_colors = ("#306998", "#E69F00", "#009E73")
+# Subcategory colors: use Okabe-Ito palette starting with brand green
+subcategory_colors = OKABE_ITO[:3]
 
 # Build full color tuple: repeat pattern for each department group
 all_colors = subcategory_colors * len(departments)
 
-# Custom style for large canvas with increased font sizes
 custom_style = Style(
-    background="white",
-    plot_background="white",
-    foreground="#333333",
-    foreground_strong="#333333",
-    foreground_subtle="#666666",
+    background=PAGE_BG,
+    plot_background=PAGE_BG,
+    foreground=INK,
+    foreground_strong=INK,
+    foreground_subtle=INK_MUTED,
     colors=all_colors,
-    title_font_size=72,
-    label_font_size=44,
-    major_label_font_size=40,
-    legend_font_size=48,
-    value_font_size=32,
+    title_font_size=28,
+    label_font_size=22,
+    major_label_font_size=18,
+    legend_font_size=16,
+    value_font_size=14,
     opacity=0.85,
     opacity_hover=1.0,
 )
 
 # Create box chart with legend showing only 3 experience levels
-# Set y-axis range to focus on actual data range (35-110)
 chart = pygal.Box(
     width=4800,
     height=2700,
     style=custom_style,
-    title="box-grouped · pygal · pyplots.ai",
+    title="box-grouped · pygal · anyplot.ai",
     x_title="Department",
     y_title="Performance Score",
     show_legend=True,
@@ -79,8 +86,10 @@
     margin=80,
     box_mode="tukey",
     x_label_rotation=0,
+    yrange=(35, 110),
     range=(35, 110),
     y_labels=[40, 50, 60, 70, 80, 90, 100, 110],
+    dots_size=8,
 )
 
 # Track which experience levels have been labeled in legend
@@ -103,5 +112,5 @@
 chart.x_labels = x_labels
 
 # Save outputs
-chart.render_to_file("plot.html")
-chart.render_to_png("plot.png")
+chart.render_to_file(f"plot-{THEME}.html")
+chart.render_to_png(f"plot-{THEME}.png")

plots/box-grouped/metadata/python/pygal.yaml

@@ -1,32 +1,245 @@
 library: pygal
+language: python
 specification_id: box-grouped
 created: '2025-12-25T19:57:08Z'
-updated: '2025-12-25T20:27:17Z'
-generated_by: claude-opus-4-5-20251101
-workflow_run: 20510142994
+updated: '2026-05-08T03:42:31Z'
+generated_by: claude-haiku
+workflow_run: 25535051660
 issue: 2017
-python_version: 3.13.11
+python_version: 3.13.13
 library_version: 3.1.0
-preview_url: https://storage.googleapis.com/anyplot-images/plots/box-grouped/pygal/plot.png
-preview_html: https://storage.googleapis.com/anyplot-images/plots/box-grouped/pygal/plot.html
+preview_url_light: https://storage.googleapis.com/anyplot-images/plots/box-grouped/python/pygal/plot-light.png
+preview_url_dark: https://storage.googleapis.com/anyplot-images/plots/box-grouped/python/pygal/plot-dark.png
+preview_html_light: https://storage.googleapis.com/anyplot-images/plots/box-grouped/python/pygal/plot-light.html
+preview_html_dark: https://storage.googleapis.com/anyplot-images/plots/box-grouped/python/pygal/plot-dark.html
 quality_score: 85
+review:
+  strengths:
+  - Perfect text legibility in both light and dark themes with explicit font sizing
+  - Flawless palette compliance - first series is brand green (#009E73), Okabe-Ito
+    colors in correct order, theme-adaptive chrome perfect
+  - Excellent spec compliance - grouped box plot correctly shows side-by-side boxes
+    with distinct colors and legend
+  - Realistic, neutral data scenario (employee performance by department and level)
+    with authentic distributions and outliers
+  - Clean, reproducible code with proper seed, KISS structure, and correct pygal API
+    usage
+  weaknesses:
+  - Design could be more sophisticated - well-configured defaults but lacks visual
+    distinctiveness or intentional hierarchy
+  - Visual refinement could be improved - top and right spines remain; could be removed
+    for cleaner aesthetic
+  - No visual storytelling - plot displays data without emphasis on insights (e.g.,
+    which department/level combinations excel)
+  image_description: |-
+    Light render (plot-light.png):
+      Background: Warm off-white (#FAF8F1) with subtle top border
+      Chrome: Title "box-grouped · pygal · anyplot.ai" at top center, axis labels "Department" (X) and "Performance Score" (Y) clearly visible, tick labels readable, subtle horizontal grid lines
+      Data: 9 grouped box plots (3 departments × 3 experience levels) with green (#009E73, Junior), orange (#D55E00, Senior), and blue (#0072B2, Lead) boxes. Whiskers extend to 1.5×IQR, outliers shown as dots. Box widths consistent across groups.
+      Legend: Bottom-center, three entries showing Junior/Senior/Lead with corresponding colors
+      Legibility verdict: PASS - All text readable, colors distinct, plot well-balanced on canvas
+
+    Dark render (plot-dark.png):
+      Background: Warm near-black (#1A1A17) with subtle top border
+      Chrome: Title visible in light color, axis labels readable, tick labels all readable in light color against dark background (no dark-on-dark failures), subtle horizontal grid lines
+      Data: Identical to light render - same 9 grouped boxes with green, orange, blue colors. Whiskers and outliers clearly visible against dark background. Box colors are identical to light render (only chrome flipped).
+      Legend: Bottom-center, same three entries
+      Legibility verdict: PASS - All text readable, no dark-on-dark failures, data colors identical to light render, excellent theme adaptation
+  criteria_checklist:
+    visual_quality:
+      score: 30
+      max: 30
+      items:
+      - id: VQ-01
+        name: Text Legibility
+        score: 8
+        max: 8
+        passed: true
+        comment: All font sizes explicitly set (title 28px, labels 22px, major labels
+          18px, legend 16px), perfectly readable in both themes
+      - id: VQ-02
+        name: No Overlap
+        score: 6
+        max: 6
+        passed: true
+        comment: No overlapping text, department labels centered using clever x_labels
+          positioning, all elements readable
+      - id: VQ-03
+        name: Element Visibility
+        score: 6
+        max: 6
+        passed: true
+        comment: 9 box plots clearly visible with optimized sizing for moderate data
+          density, whiskers and outliers well visible
+      - id: VQ-04
+        name: Color Accessibility
+        score: 2
+        max: 2
+        passed: true
+        comment: Okabe-Ito colors 1-3 (green, orange, blue) are colorblind-safe, excellent
+          contrast between boxes and backgrounds
+      - id: VQ-05
+        name: Layout & Canvas
+        score: 4
+        max: 4
+        passed: true
+        comment: Plot fills 60-70% of canvas with generous 80px margins, well-balanced
+          layout, legend positioned appropriately
+      - id: VQ-06
+        name: Axis Labels & Title
+        score: 2
+        max: 2
+        passed: true
+        comment: 'Descriptive labels: ''Department'' (X), ''Performance Score'' (Y),
+          with appropriate title format'
+      - id: VQ-07
+        name: Palette Compliance
+        score: 2
+        max: 2
+        passed: true
+        comment: 'First series #009E73 (brand green), multi-series follows Okabe-Ito
+          order, backgrounds #FAF8F1 (light) and #1A1A17 (dark), theme chrome perfect
+          in both renders'
+    design_excellence:
+      score: 8
+      max: 20
+      items:
+      - id: DE-01
+        name: Aesthetic Sophistication
+        score: 4
+        max: 8
+        passed: false
+        comment: Well-configured library defaults with custom Style and Okabe-Ito
+          palette, professional but generic - no exceptional design thought
+      - id: DE-02
+        name: Visual Refinement
+        score: 2
+        max: 6
+        passed: false
+        comment: Minimal customization - Y-grid shown (appropriate) but all four spines
+          remain (could remove top/right for cleaner look)
+      - id: DE-03
+        name: Data Storytelling
+        score: 2
+        max: 6
+        passed: false
+        comment: Plot displays distributions across departments and levels clearly,
+          but lacks visual emphasis or hierarchy to highlight insights
+    spec_compliance:
+      score: 15
+      max: 15
+      items:
+      - id: SC-01
+        name: Plot Type
+        score: 5
+        max: 5
+        passed: true
+        comment: Perfect grouped box plot implementation with side-by-side boxes
+      - id: SC-02
+        name: Required Features
+        score: 4
+        max: 4
+        passed: true
+        comment: 'All features present: boxes side-by-side, distinct colors, clear
+          legend, consistent widths, box/whiskers/outliers'
+      - id: SC-03
+        name: Data Mapping
+        score: 3
+        max: 3
+        passed: true
+        comment: X-axis departments, Y-axis performance scores, subcategories as grouped
+          boxes
+      - id: SC-04
+        name: Title & Legend
+        score: 3
+        max: 3
+        passed: true
+        comment: Title 'box-grouped · pygal · anyplot.ai' correct, legend labels accurate
+          (Junior/Senior/Lead)
+    data_quality:
+      score: 15
+      max: 15
+      items:
+      - id: DQ-01
+        name: Feature Coverage
+        score: 6
+        max: 6
+        passed: true
+        comment: 'All aspects shown: tight distributions (Engineering) and wide distributions
+          (Sales), experience progression, outliers in multiple groups'
+      - id: DQ-02
+        name: Realistic Context
+        score: 5
+        max: 5
+        passed: true
+        comment: Employee performance by department/level - authentic business scenario,
+          neutral, realistic patterns (seniority correlation)
+      - id: DQ-03
+        name: Appropriate Scale
+        score: 4
+        max: 4
+        passed: true
+        comment: Performance range 35-110 (realistic for performance score), distributions
+          logically follow experience levels
+    code_quality:
+      score: 10
+      max: 10
+      items:
+      - id: CQ-01
+        name: KISS Structure
+        score: 3
+        max: 3
+        passed: true
+        comment: 'Simple linear flow: imports → constants → data → chart → save, no
+          functions/classes'
+      - id: CQ-02
+        name: Reproducibility
+        score: 2
+        max: 2
+        passed: true
+        comment: np.random.seed(42) set, deterministic data generation
+      - id: CQ-03
+        name: Clean Imports
+        score: 2
+        max: 2
+        passed: true
+        comment: 'Only used imports: os, numpy, pygal, Style'
+      - id: CQ-04
+        name: Code Elegance
+        score: 2
+        max: 2
+        passed: true
+        comment: Appropriate complexity, no over-engineering, no fake functionality
+      - id: CQ-05
+        name: Output & API
+        score: 1
+        max: 1
+        passed: true
+        comment: 'Correct output: plot-{THEME}.html and plot-{THEME}.png'
+    library_mastery:
+      score: 7
+      max: 10
+      items:
+      - id: LM-01
+        name: Idiomatic Usage
+        score: 4
+        max: 5
+        passed: true
+        comment: Proper use of pygal.Box(), Style customization, chart.add(), legend
+          management. Fairly standard high-level API usage.
+      - id: LM-02
+        name: Distinctive Features
+        score: 3
+        max: 5
+        passed: true
+        comment: Uses Style for theme adaptation and custom legend tracking (showing
+          each level only once) - somewhat distinctive but still within standard practices
+  verdict: APPROVED
 impl_tags:
   dependencies: []
   techniques: []
   patterns:
-    - data-generation
+  - data-generation
+  - iteration-over-groups
   dataprep: []
   styling: []
-review:
-  strengths:
-  - Colorblind-safe color palette (blue, orange, teal) provides excellent accessibility
-  - Clean legend placement at bottom with 3 columns showing experience levels clearly
-  - Realistic employee performance data context with meaningful variation between
-    groups
-  - Proper use of box_mode=tukey for standard box plot whisker calculation
-  - Well-structured code following KISS principles with fixed random seed
-  weaknesses:
-  - Y-axis renders from 0 despite range=(35, 110) setting, creating excessive whitespace
-    below the data
-  - Outlier markers are very small dots that are difficult to see clearly
-  - Grid lines are somewhat prominent and could be more subtle for better visual balance