---
id: yte
version: "1.9.4"
license: MIT
license_treatment: permissive
maintenance: aging
---

# yte — A YAML template engine with Python expressions

License: permissive · Maintenance: aging · Downloads: 168.8K/mo

## What it is and what it does

YTE is a template engine purpose-built for YAML that lets you embed Python expressions directly into YAML files to generate dynamic configurations. Instead of learning a separate templating syntax, you mark Python expressions with a `?` prefix anywhere in your YAML, and YTE evaluates them to produce plain YAML output. The key advantage is that YTE templates remain valid YAML files themselves—the `?` expressions are just strings to the YAML parser—and whitespace handling works naturally without the tuning required by generic engines like Jinja2.

The package depends on argparse-dataclass, dpath, and pyyaml to parse command-line arguments, navigate nested data structures, and handle YAML serialization. It's designed for developers who want to avoid learning a new templating language and prefer to write Python expressions in their YAML configurations instead.

Use it for:

- Generate Kubernetes manifests or Docker Compose files with conditional blocks and loops based on deployment environment.
- Build configuration files for infrastructure-as-code tools where Python logic simplifies conditional sections.
- Template CI/CD pipeline definitions (GitHub Actions, GitLab CI) with dynamic job matrices and conditional steps.
- Create parameterized YAML schemas for application config where expressions compute derived values.
- Preprocess YAML data files with Python logic before passing them to downstream tools.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

YTE is a YAML template engine that embeds Python expressions directly into YAML files to dynamically generate YAML documents, using a `?` prefix to mark expressions for evaluation.

Yes, if you need to template YAML files and prefer Python expressions over a separate templating language. The low install friction, permissive license, and lack of security vulnerabilities make it a safe choice. The aging maintenance status is a minor concern—the project is stable and unarchived, but verify that the feature set and performance meet your needs before adopting it for critical workflows.

## Install

pip install yte
uv add yte
poetry add yte

## Installing yte

Before you install: Low install friction with a pure-Python wheel. Maintenance status is aging—last release was 260 days ago—but the repository remains active and unarchived, suggesting the project is stable rather than abandoned.

License in practice: MIT license is permissive, allowing use in commercial and proprietary projects with minimal restrictions beyond attribution.

Quickstart:

pip install yte

import yte
rendered = yte.render_string('key: ? 1 + 1')
print(rendered)  # key: 2

Requires Python 3.8 or later (supports current versions up to Python 3.x).

Verify before relying:

- Whether YTE's performance is suitable for large or deeply nested YAML files.
- How error messages and debugging experience compare to other YAML template engines.
- Whether the package is actively maintained or in maintenance-only mode given the 260-day gap since last release.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: aging
- Downloads: 168.8K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

yaml template engine, dynamic yaml generation, python yaml templating, yaml with expressions, yaml configuration templating, template yaml files, yaml preprocessing, yaml-templating, configuration-generation, python-expressions

[View on SkillFed](https://skillfed.io/packages/yte) · [View on PyPI](https://pypi.org/project/yte/)