larzchart

Data to inline SVG charts, in pure Python. Zero dependencies.

No matplotlib, no numpy, no browser, no fonts to bundle. Give it numbers, get back a self-contained <svg> string you can drop straight into an HTML page, an email, a README, a dashboard, or a larzmark site — rendered on the server, in a few kilobytes.

from larzchart import LineChart, BarChart, PieChart, Sparkline, Series

svg = LineChart(
    {"revenue": [10, 14, 12, 20, 25], "cost": [8, 9, 11, 12, 15]},
    labels=["Jan", "Feb", "Mar", "Apr", "May"],
    title="Q1 performance", theme="dark",
).render()                       # -> '<svg ...>...</svg>'

Sparkline([3, 5, 2, 8, 6, 9]).render()      # a tiny inline trend line

Why

• Zero dependencies. Pure standard library. Nothing to compile, no native wheels, works anywhere Python does — including tiny/serverless environments where matplotlib won't fit.
• Server-side & inline. Output is a self-contained SVG string (inline styles, no external fonts or scripts), so it renders in an email or a static page with no JavaScript and no image files to host.
• Just numbers in. Accepts a bare list, a dict of name -> values, or Series objects. Multi-series, titles, axes, gridlines, legends handled for you.
• Themed. Light and dark themes and a ten-colour categorical palette out of the box; set per-series colours when you want.
• Deterministic. The same data always produces the same SVG — great for snapshot tests and reproducible reports.

Install

pip install larzchart

Chart types

from larzchart import LineChart, AreaChart, BarChart, PieChart, Sparkline

LineChart([1, 4, 2, 8, 5]).render()                       # line
AreaChart([1, 4, 2, 8, 5]).render()                       # filled area
BarChart({"a": [3, 5, 2], "b": [4, 1, 6]}).render()       # grouped bars
PieChart([30, 50, 20], labels=["A", "B", "C"]).render()   # pie
PieChart([30, 50, 20], donut=True).render()               # donut
Sparkline([3, 5, 2, 8, 6, 9]).render()                    # inline mini-line

Common options: title, labels, width, height, theme="light"|"dark", legend=True/False, and per-Series color.

Save to a file

LineChart([1, 2, 3, 4]).to_html("chart.html")     # minimal standalone HTML page

Great with the rest of the stack

Feed it query results from larzdb, embed the SVG in a page built by larzmark, or drop a Sparkline into a report — no image pipeline required.

Tests

python -m unittest discover -s tests -v      # 25 tests, valid-XML checks, zero deps

The Larz stack

Pure-Python, zero-dependency building blocks:

• larz — money-native web framework
• larzchain — from-scratch PoW blockchain
• larzmoney — exact, penny-perfect money
• larzcrypt — pure-Python cryptography toolkit
• larzdb — crash-safe embedded database
• larzagent — zero-dep AI agent framework
• larzchart — this library

License

MIT © larz-scripter