Graphify-Labs/graphify · error · ImportError

matplotlib not installed. Run: pip install matplotlib

Error message

matplotlib not installed. Run: pip install matplotlib

What it means

Raised by graphify's Markdown graph exporter when matplotlib is not importable. matplotlib is an optional dependency used only for the static PNG/SVG community layout (spring_layout on a dark figure), so graphify guards the import and converts the underlying ImportError into an actionable message rather than failing at module load.

Solutions

  1. pip install matplotlib
  2. Or reinstall graphify with the visualization extra if one is documented (e.g. `pip install graphify[viz]`)
  3. If the install reports success but the error persists, verify in the same interpreter: `python -c "import matplotlib"` and check for missing system libraries
  4. If you don't need the static image, use the HTML or DOT exporters instead, which have no matplotlib dependency

Example fix

# before
graphify export --markdown graph.png   # ImportError: matplotlib not installed

# after
pip install matplotlib
graphify export --markdown graph.png
Defensive patterns

Strategy: validation

Validate before calling

import importlib.util

matplotlib_ok = importlib.util.find_spec("matplotlib") is not None
if not matplotlib_ok:
    print("matplotlib missing - skipping markdown image export")
else:
    export_markdown_graph(G, communities, "graph.png")

Try / catch

try:
    export_markdown_graph(G, communities, "graph.png")
except ImportError as e:
    if "matplotlib" in str(e):
        print(f"skipping image export: {e}")
    else:
        raise

Prevention

When it happens

Trigger: Calling the markdown-embedding export function (to_markdown_graph / export with matplotlib output) in an environment where `import matplotlib` (or matplotlib.pyplot) raises ImportError — e.g. the base graphify install without the viz extra, or a venv where matplotlib was never installed.

Common situations: Installing graphify via `pip install graphify` (core extras only) and then requesting the matplotlib-based markdown graph; running in a slim container/CI image; a broken matplotlib install (missing system libs like libpng) also surfaces as ImportError here.

Related errors

AI-assisted analysis of Graphify-Labs/graphify@7fe58b0b0f (2026-08-14). Data as JSON: /api/errors/a9b0e50728e96f90. Report an issue: GitHub.

Appendix: source

Thrown at graphify/export.py:1102

    communities: dict[int, list[str]],
    output_path: str,
    community_labels: dict[int, str] | None = None,
    figsize: tuple[int, int] = (20, 14),
) -> None:
    """Export graph as an SVG file using matplotlib + spring layout.

    Lightweight and embeddable - works in Obsidian notes, Notion, GitHub READMEs,
    and any markdown renderer. No JavaScript required.

    Node size scales with degree. Community colors match the HTML output.
    """
    try:
        import matplotlib
        matplotlib.use("Agg")
        import matplotlib.pyplot as plt
        import matplotlib.patches as mpatches
    except ImportError as e:
        raise ImportError("matplotlib not installed. Run: pip install matplotlib") from e

    node_community = _node_community_map(communities)

    fig, ax = plt.subplots(figsize=figsize, facecolor="#1a1a2e")
    ax.set_facecolor("#1a1a2e")
    ax.axis("off")

    pos = nx.spring_layout(G, seed=42, k=2.0 / (G.number_of_nodes() ** 0.5 + 1))

    degree = dict(G.degree())
    max_deg = max(degree.values(), default=1) or 1

    node_colors = [COMMUNITY_COLORS[node_community.get(n, 0) % len(COMMUNITY_COLORS)] for n in G.nodes()]
    node_sizes = [300 + 1200 * (degree.get(n, 1) / max_deg) for n in G.nodes()]

    # Draw edges - dashed for non-EXTRACTED
    for u, v, data in G.edges(data=True):
        conf = data.get("confidence", "EXTRACTED")

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