Gantt Chart Generator

Generate horizontal Gantt charts from schedule data via the bundled scripts/gantt.py toolkit. The gantt() function accepts a DataFrame or file path plus column names, and saves a PNG (returning the path). It handles theming, date parsing, bar colour-coding, completion overlays, today-line, legend, and saving.

Instructions

1. Provide the data source: a pandas DataFrame, or a path to a .csv / .tsv / .json file.

   • One row = one task / phase.
   • Required columns: a phase/task name column, a start date column, and either an end date column OR a duration-in-days column.

2. Import and call gantt():

import sys
sys.path.insert(0, "scripts")   # adjust path to where gantt.py is deployed
from gantt import gantt

# Basic — start + end columns
gantt("schedule.csv", phase="Phase", start="Start", end="End",
      title="Project Schedule", out="gantt.png")

# Group colour-coding + today line
gantt(df, phase="phase", start="planned_start", end="planned_end",
      group="project", today=True, out="schedule.png")

# Duration instead of end date
gantt(df, phase="task", start="start_date", duration="days",
      out="schedule.png")

# Completion % hatch overlay
gantt(df, phase="Phase", start="Start", end="End",
      completion="PctDone", out="gantt.png")

3. See references/cheatsheet.md for full parameter reference and CLI examples.

Bundled files

• scripts/gantt.py — the full toolkit (load_data, apply_theme, save_fig, gantt, CLI)
• references/cheatsheet.md — parameter quick-reference and copy-paste examples
• assets/sample_schedule.csv — demo dataset that exercises every feature

Defaults & behaviour

• Colorblind-friendly palette (matches chart-builder skill for visual consistency).
• Date axis auto-scales: weekly ticks ≤90 days, monthly ≤365 days, bi-monthly beyond.
• Bars ordered top-to-bottom matching input row order.
• Rows with missing phase or start values are silently dropped before drawing.
• Output PNG at 150 DPI by default.
• Provide end OR duration — not both; end takes priority if both are present.

Run this — do not improvise

This capability's deterministic implementation is a RAPP single-file agent, linked beside this file as gantt_chart_generator_agent.py and embedded as the fenced Python below (sha256 301a1e3447da6048…; a byte-exact copy is also vaulted in the capsule comment at the end of this file). On a host with sandbox execution, run the linked file directly — if it is missing, write the fence contents verbatim to gantt_chart_generator_agent.py first:

python3 gantt_chart_generator_agent.py '{"key": "value"}'      # arguments as one JSON object
echo '{"key": "value"}' | python3 gantt_chart_generator_agent.py   # or on stdin
python3 gantt_chart_generator_agent.py --tool                      # emit the JSON tool contract

Treat stdout as a tool result. If it reports missing or unresolved inputs, stop and collect them. If it returns steps, execute those steps in order exactly as returned; if it returns instructions, follow them with the supplied inputs. Otherwise use the result verbatim. Do not invent behavior beyond that output. On a host without code execution, treat the Parameters schema and the code below as the exact specification and never paraphrase a step. Never edit inside the generated markers; a converter-equipped host can instead restore the original file checksum-verified with the installed rapp-agent-converter/scripts/toast.py convert SKILL.md --to agent.

"""GanttChartGenerator -- Use this skill whenever the user asks to visualize a project schedule, timeline, Gantt chart, or phase/task breakdown over time. It gives the agent a prebuilt, parameterized gantt() function so Gantt charts are produced instantly and consistently — with colour-coded groups, completion overlays, a today reference line, and auto-scaled date axes — instead of hand-writing matplotlib each time.

Generated by the rapp skill from gantt-chart-generator. The RCI capsule at the bottom of this file carries the full original; `toast.py convert` restores it byte-exact."""

import json
import re
import sys

try:
    from agents.basic_agent import BasicAgent
except ImportError:  # running OUTSIDE a brainstem -- stay executable anyway.
    class BasicAgent:  # noqa: D101 - minimal stand-in, same contract
        def __init__(self, name=None, metadata=None):
            if name:
                self.name = name
            if metadata:
                self.metadata = metadata

        def perform(self, **kwargs):
            return "Not implemented."

        def system_context(self):
            return None

        def to_tool(self):
            return {"type": "function", "function": {
                "name": self.name,
                "description": self.metadata.get("description", ""),
                "parameters": self.metadata.get("parameters", {})}}

# The procedural layer, verbatim from the source capability.
INSTRUCTIONS = 'Generate horizontal Gantt charts from schedule data via the bundled `scripts/gantt.py` toolkit.\nThe `gantt()` function accepts a DataFrame or file path plus column names, and saves a PNG (returning the path).\nIt handles theming, date parsing, bar colour-coding, completion overlays, today-line, legend, and saving.\n\n## Instructions\n\n1. Provide the data source: a pandas DataFrame, or a path to a `.csv` / `.tsv` / `.json` file.\n   - One row = one task / phase.\n   - Required columns: a **phase/task name** column, a **start date** column, and either an **end date** column OR a **duration-in-days** column.\n\n2. Import and call `gantt()`:\n\n```python\nimport sys\nsys.path.insert(0, "scripts")   # adjust path to where gantt.py is deployed\nfrom gantt import gantt\n\n# Basic — start + end columns\ngantt("schedule.csv", phase="Phase", start="Start", end="End",\n      title="Project Schedule", out="gantt.png")\n\n# Group colour-coding + today line\ngantt(df, phase="phase", start="planned_start", end="planned_end",\n      group="project", today=True, out="schedule.png")\n\n# Duration instead of end date\ngantt(df, phase="task", start="start_date", duration="days",\n      out="schedule.png")\n\n# Completion % hatch overlay\ngantt(df, phase="Phase", start="Start", end="End",\n      completion="PctDone", out="gantt.png")\n```\n\n3. See `references/cheatsheet.md` for full parameter reference and CLI examples.\n\n## Bundled files\n- `scripts/gantt.py`      — the full toolkit (load_data, apply_theme, save_fig, gantt, CLI)\n- `references/cheatsheet.md` — parameter quick-reference and copy-paste examples\n- `assets/sample_schedule.csv` — demo dataset that exercises every feature\n\n## Defaults & behaviour\n- Colorblind-friendly palette (matches chart-builder skill for visual consistency).\n- Date axis auto-scales: weekly ticks ≤90 days, monthly ≤365 days, bi-monthly beyond.\n- Bars ordered top-to-bottom matching input row order.\n- Rows with missing phase or start values are silently dropped before drawing.\n- Output PNG at 150 DPI by default.\n- Provide `end` OR `duration` — not both; `end` takes priority if both are present.'

# Ordered commands lifted verbatim from the capability's own documentation.
STEPS = []


class GanttChartGeneratorAgent(BasicAgent):
    def __init__(self):
        self.name = 'GanttChartGenerator'
        self.metadata = {
          "name": "GanttChartGenerator",
          "description": "Use this skill whenever the user asks to visualize a project schedule, timeline, Gantt chart, or phase/task breakdown over time. It gives the agent a prebuilt, parameterized gantt() function so Gantt charts are produced instantly and consistently \u2014 with colour-coded groups, completion overlays, a today reference line, and auto-scaled date axes \u2014 instead of hand-writing matplotlib each time.",
          "parameters": {
            "type": "object",
            "properties": {},
            "required": []
          }
        }
        super().__init__(name=self.name, metadata=self.metadata)

    def perform(self, **kwargs):  # toaster:generated-perform
        return json.dumps({"status": "ok", "instructions": INSTRUCTIONS,
                           "inputs": kwargs,
                           "note": "Prose-only capability: follow INSTRUCTIONS "
                                   "with the given inputs."}, indent=2)

if __name__ == "__main__":
    #     echo '{"arg": "value"}' | python3 gantt_chart_generator_agent.py
    #     python3 gantt_chart_generator_agent.py '{"arg": "value"}'
    #     python3 gantt_chart_generator_agent.py --tool          # emit the JSON tool contract
    _a = sys.argv[1:]
    if _a and _a[0] == "--tool":
        print(json.dumps(GanttChartGeneratorAgent().to_tool(), indent=2))
    else:
        _raw = _a[0] if _a else (sys.stdin.read().strip() or "{}")
        print(GanttChartGeneratorAgent().perform(**json.loads(_raw)))

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