pygotpl

pygotpl publishes gotpl, a pure Python implementation of Go's text/template and html/template, with Sprig v3 compatibility and separate synchronous and asynchronous rendering paths. Runtime use requires no Go installation, subprocess, shared library, or compiled extension.

pygotpl is pre-1.0. Completed areas have oracle-backed compatibility evidence, while the complete Go text/template and html/template surfaces remain classified as partial. Check the compatibility contract before relying on a specific Go behavior.

Installation

python -m pip install gotpl

Optional cryptographic and Helm capabilities are available through the crypto and helm extras. gotpl installs its compatible goduration and gotime dependencies automatically. See Getting Started for the exact commands and supported Python versions.

Quick Start

Render a text template once:

import gotpl

result = gotpl.render("Hello {{.Name}}", {"Name": "Gopher"})
assert result == "Hello Gopher"

Compile a template when the same source will be rendered repeatedly:

import gotpl

greeting = gotpl.Template("Hello {{.Name}}")

assert greeting.render({"Name": "Ada"}) == "Hello Ada"
assert greeting.render({"Name": "Linus"}) == "Hello Linus"

For HTML output, use the contextual HTML API rather than escaping a completed string:

import gotpl

result = gotpl.render_html(
    '<a href="/search?q={{.Query}}">{{.Label}}</a>',
    {"Query": "python & go", "Label": "<Search>"},
)

assert result == '<a href="/search?q=python%20%26%20go">&lt;Search&gt;</a>'

Where to Go Next

• Getting Started — installation, repeated renders, and registering Python functions.
• Template Language — pipelines, control flow, variables, associations, and built-ins.
• Reusable Templates and Environments — choose Template, HTMLTemplate, Environment, or TemplateEngine; load named sources; and reuse immutable configuration.
• Async Rendering — async callbacks, writers, cancellation, and concurrency.
• HTML Templates — contextual escaping and trusted content.
• Function Libraries — Sprig, Slim-Sprig, Sprout, Helm-compatible functions, and Python-native helpers.
• Runtime Extensions — context-aware integrations, associated rendering, capabilities, and extension authoring.
• Sandboxing — policies, budgets, and the security boundary.
• Build an HTML Site — a Jinja2-style template directory with reusable header and footer definitions.
• Helm Functions and Runtime and Build a Helm Renderer — reusable Helm APIs and the complete local-chart application workflow.
• API Overview — the candidate 1.0 public surface.
• Compatibility and Performance — measured support and benchmark evidence.

The generated documentation site is published at http://blog.kyonr.com/pygotpl/.

Development

Development dependencies are locked with uv. Go is needed only for reference oracles and comparative benchmarks.

uv sync --frozen --all-groups --extra crypto
./scripts/check.sh

See Contributing, Testing, and the active M10 milestone before changing compatibility behavior.

License

Copyright 2026 Revolution1. Original project work is licensed under the Apache License 2.0. Upstream terms and attribution are recorded in Third-Party Notices.