Gantt charts

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Gantt charts are useful for showing a project plan, a publication timeline, or any other schedule organized along a numeric time axis. tikzfigure provides a small structured wrapper around LaTeX’s pgfgantt package.

The package is added automatically when you create a chart, so the same figure can be exported with generate_standalone() or compiled with show().

from tikzfigure import TikzFigure

A simple project plan

Pass the first and last time slot to gantt() and describe rows with small dictionaries. The supported row types are title, titlelist, group, bar, milestone, link, and raw.

fig = TikzFigure()
fig.gantt(
    1,
    12,
    options=["hgrid", "vgrid"],
    rows=[
        {"type": "titlelist", "content": "1,2,3,4,5,6,7,8,9,10,11,12"},
        {"type": "group", "content": "Discovery", "start": 1, "end": 3},
        {"type": "bar", "content": "Research", "start": 1, "end": 2},
        {"type": "bar", "content": "Requirements", "start": 2, "end": 3},
        {"type": "group", "content": "Delivery", "start": 4, "end": 12},
        {"type": "bar", "content": "Implementation", "start": 4, "end": 8},
        {"type": "bar", "content": "Testing", "start": 8, "end": 10},
        {"type": "milestone", "content": "Release", "at": 12},
    ],
)

print(fig.generate_tikz())

% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \begin{ganttchart}[hgrid, vgrid]{1}{12}
        \gantttitlelist{1,2,3,4,5,6,7,8,9,10,11,12}{1}\\
        \ganttgroup{Discovery}{1}{3}\\
        \ganttbar{Research}{1}{2}\\
        \ganttbar{Requirements}{2}{3}\\
        \ganttgroup{Delivery}{4}{12}\\
        \ganttbar{Implementation}{4}{8}\\
        \ganttbar{Testing}{8}{10}\\
        \ganttmilestone{Release}{12}\\
    \end{ganttchart}
\end{tikzpicture}

Call fig.show() in a notebook to compile and display the chart, or save it with fig.savefig("project-plan.pdf").

Dependencies between tasks

Give bars and milestones a name and connect them with link rows. The names are passed to pgfgantt and are used by ganttlink.

fig = TikzFigure()
chart = fig.add_gantt_chart(
    1,
    8,
    options=["hgrid", "vgrid"],
)

chart.add_row(
    "titlelist",
    content="Jan,Feb,Mar,Apr,May,Jun,Jul,Aug",
    width=1,
    # Text labels must not be run through pgfmath's default numeric
    # evaluation, which pgfgantt otherwise applies to titlelist entries.
    options=[r"title list options={var=\x}"],
)
chart.add_row(
    "bar",
    content="Design",
    start=1,
    end=3,
    name="design",
    options=["progress=100"],
)
chart.add_row(
    "bar",
    content="Build",
    start=3,
    end=6,
    name="build",
    options=["progress=60"],
)
chart.add_row("milestone", content="Launch", at=8, name="launch")
chart.add_row("link", source="design", target="build")
chart.add_row("link", source="build", target="launch")

fig.show()

/home/runner/work/tikzfigure/tikzfigure/.venv/lib/python3.12/site-packages/fitz/__init__.py:17: FutureWarning: The `fitz` API is deprecated and will be removed in future. Use `import pymupdf` instead.
  warnings.warn(

add_gantt_chart() is the explicit spelling; gantt() and add_gantt() are short aliases. The returned GanttChart can be extended incrementally with add_row(), which is convenient when rows come from application data.

A multi-phase project timeline

This example mirrors a common plotting API: task names, starts, and durations are kept in parallel Python lists. Convert each phase into Gantt rows and use per-bar options to give the phases distinct colors.

phase1_tasks = ["Requirements", "Architecture", "UI Design"]
phase1_starts = [0, 3, 6]
phase1_durations = [3, 3, 4]

phase2_tasks = ["Backend Dev", "Frontend Dev", "Integration"]
phase2_starts = [10, 10, 20]
phase2_durations = [10, 10, 5]

phase3_tasks = ["Unit Tests", "Integration Tests", "UAT"]
phase3_starts = [25, 28, 32]
phase3_durations = [3, 4, 3]


def phase_rows(title, tasks, starts, durations, fill, draw):
    rows = [
        {
            "type": "group",
            "content": title,
            "start": min(starts),
            "end": max(start + duration for start, duration in zip(starts, durations)),
        }
    ]
    rows.extend(
        {
            "type": "bar",
            "content": task,
            "start": start,
            "end": start + duration,
            # pgfgantt bars are styled via the `bar` style itself, not raw
            # `fill=`/`draw=` keys (those live outside the /pgfgantt family).
            "options": [f"bar/.append style={{fill={fill}, draw={draw}}}"],
        }
        for task, start, duration in zip(tasks, starts, durations)
    )
    return rows


rows = [{"type": "titlelist", "content": ",".join(str(i) for i in range(36))}]
rows += phase_rows(
    "Planning", phase1_tasks, phase1_starts, phase1_durations, "LightBlue", "blue"
)
rows += phase_rows(
    "Development", phase2_tasks, phase2_starts, phase2_durations, "LightGreen", "green"
)
rows += phase_rows(
    "Testing", phase3_tasks, phase3_starts, phase3_durations, "LightYellow", "orange"
)

fig = TikzFigure()
fig.gantt(0, 35, rows=rows, options=["hgrid", "vgrid", "bar height=.6"])
fig.show()

Team resource allocation

The same row-building pattern works when each row represents a person rather than a project phase.

team_members = ["Alice", "Bob", "Charlie", "Diana", "Eve"]
task_starts = [0, 5, 3, 8, 10]
task_durations = [8, 6, 10, 7, 5]

team_rows = [{"type": "titlelist", "content": ",".join(str(i) for i in range(19))}]
team_rows.extend(
    {
        "type": "bar",
        "content": member,
        "start": start,
        "end": start + duration,
        "options": ["bar/.append style={fill=Coral, draw=DarkRed, fill opacity=.7}"],
    }
    for member, start, duration in zip(team_members, task_starts, task_durations)
)

fig = TikzFigure()
fig.gantt(0, 18, rows=team_rows, options=["hgrid", "vgrid"])
fig.show()

Rows are ordinary dictionaries, so they can be generated from CSV files, database records, or any other application data. Use a raw row when a pgfgantt command is not covered by the structured row types.