Getting started

Last Updated: 2026-06-10 Status: 🟢 APPROVATO — allineato al contratto v0.8.0.

Build a first page in five minutes.

Install

pip install genro-builders

A first HTML page

A page is a builder: subclass the dialect, implement main(self, root), run the two-phase lifecycle (create() then render()).

from genro_builders.contrib.html import HtmlBuilder


class HelloPage(HtmlBuilder):
    def main(self, root):
        body = root.body()
        body.h1("Hello, world")
        body.p("This is genro-builders.")


page = HelloPage()
page.create()
print(page.render())

Output (single line, default mode):

<body><h1>Hello, world</h1><p>This is genro-builders.</p></body>

For indented output:

print(page.render(pretty=True))

What just happened

  • HelloPage() instantiates the builder: grammar plus document (source bag, render lifecycle).

  • page.create() calls setup(self.data) then main(self.source). You populate the source bag using the dialect’s fluent API.

  • page.render() walks the source bag and emits markup. Renderers are renderer_<mode> properties on the builder class.

See Builders overview for the full lifecycle, including the data-bound scenario (BuilderHandler).

SVG and CSS

Same pattern, different grammar:

from genro_builders.contrib.svg import SvgBuilder

class Chart(SvgBuilder):
    def main(self, root):
        svg = root.svg(viewBox="0 0 100 100")
        svg.rect(x=10, y=10, width=80, height=80, fill="red")

c = Chart(); c.create()
print(c.render())

from genro_builders.contrib.css import CssBuilder

class Theme(CssBuilder):
    def main(self, root):
        sheet = root.stylesheet()
        card = sheet.selector(class_="card")
        card.rule(color="red", padding="10px")

t = Theme(); t.create()
print(t.render())

Next steps