ztml 0.2.5

Rust-backed framework for building websites in pure Python

ztml

A Rust-backed framework for building websites in pure Python. Define HTML, CSS, and JS using Python expressions with full autocompletion. Inspired by FastHTML.

Read my documentation

Install

pip install ztml

Quick example

from ztml import *

page = render(
    Html(
        Head(Meta().charset("utf-8"), Title("My App")),
        Body(
            H1("Hello, ztml!"),
            P("Build websites with Python.").cls("intro"),
            A("GitHub").href("https://github.com").target("_blank"),
        ),
    )
)

Every HTML element has a constructor. Attributes are set via chained builder methods. CSS is built with Rule, Media, and Keyframes, with 400+ typed property methods generated from W3C specs:

Style(
    Rule("body").margin("0").font_family("system-ui, sans-serif"),
    Rule(".container").display("flex").gap("1rem").padding("2rem"),
    Media("max-width: 768px",
        Rule(".container").flex_direction("column"),
    ),
)

The built-in server handles routing, sessions, SSE, and WebSockets:

from ztml import *
from ztml.scripts import HTMX
from ztml.server import rt, serve

@rt('/')
def get():
    return Html(
        Head(Title("Counter"), HTMX),
        Body(
            H1("Counter"),
            P("0").id("count"),
            Button("Increment").hx_post("/increment").hx_target("#count"),
        ),
    )

count = 0

@rt('/increment')
def post():
    global count
    count += 1
    return P(str(count)).id("count")

serve()  # localhost:5001

See the docs for the full guide on HTML elements, CSS styling, JavaScript helpers, custom components, and the server layer.

Examples

uv run examples/static_page.py > page.html
uv run examples/counter_server.py
uv run examples/todo_server.py
uv run examples/auth_app.py
uv run examples/ws_chat.py
uv run examples/sse_clock.py

Benchmarks

Compared against FastHTML building and rendering nested HTML element trees:

Scenario         Library      Elements   Build (ms)   Render (ms)   Total (ms)
---------------------------------------------------------------------------
10x50            ztml             1040         1.44          0.09         1.54
10x50            fasthtml         1040        14.72          2.62        17.35
                             speedup: build 10.2x, render 28.5x, total 11.3x

50x100           ztml            10200        14.65          0.90        15.55
50x100           fasthtml        10200       151.36         26.12       177.61
                             speedup: build 10.3x, render 28.9x, total 11.4x

100x200          ztml            40400        58.04          3.63        61.69
100x200          fasthtml        40400       710.79        106.00       816.57
                             speedup: build 12.2x, render 29.2x, total 13.2x

^ benchmarks/bench.py (M3 Pro MacBook Pro)

Building from source

Prerequisites: Rust toolchain, Python 3.12+, uv.

uv sync
uv run maturin develop
cargo run --bin gen_stubs --no-default-features  # regenerate .pyi stubs

Running tests

uv run python -m pytest
cargo test -p ztml-core

Releasing

Bump the version in crates/ztml-core/Cargo.toml and crates/ztml-python/Cargo.toml, make sure stubs are up to date, then:

git add -A && git commit -m "bump version to 0.x.y"
git tag v0.x.y
git push && git push origin v0.x.y

The v* tag triggers the full build matrix (Linux, macOS, Windows) and publishes to PyPI.

License

MIT