---
id: yaql
version: "3.2.0"
license: Apache-2.0
license_treatment: permissive
maintenance: aging
---

# yaql — YAQL - Yet Another Query Language

License: permissive · Maintenance: aging · Downloads: 317.0K/mo

## What it is and what it does

YAQL is a query language embedded in Python that lets you write SQL-like expressions to filter, transform, and analyze data structures. You write queries as strings (e.g., `$.customers.where($.age > 18)`) and evaluate them against Python objects, JSON, or other data; the language includes a standard library of functions for grouping, filtering, and aggregation. It's designed to be extended with custom functions, making it useful when you need a safe, user-facing query interface without building a full DSL.

The package includes a REPL for interactive exploration and can load JSON files directly. It depends on pbr for build metadata and python-dateutil for date handling. The project is aging (last release 309 days ago) but supports modern Python versions through 3.13 and has no known security vulnerabilities.

Use it for:

- Build a user-facing query interface for a web app where users filter records without writing Python code.
- Query and transform JSON data loaded from files or APIs using a familiar SQL-like syntax.
- Implement dynamic filtering and aggregation in configuration or policy engines that need to evaluate expressions safely.
- Prototype data analysis workflows interactively in the YAQL REPL before moving to production code.
- Extend OpenStack tools or other projects that already use YAQL for consistent query semantics.

## Worth the install?

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

YAQL is an embeddable query language for Python that lets you run complex queries against arbitrary objects using a SQL-like syntax with a standard library of query functions.

Yes, if you need a safe, embeddable query language for end-user filtering or data exploration. The low install friction, permissive license, and lack of security issues make it a solid choice. The aging maintenance status is a minor concern—suitable for stable, non-critical use cases; less ideal if you need active development or rapid bug fixes.

## Install

pip install yaql
uv add yaql
poetry add yaql

## Installing yaql

Before you install: Low friction to install. The package is aging (309 days since last release) but maintains support for current Python versions (3.10–3.13) and depends only on pbr and python-dateutil.

License in practice: Apache-2.0 is permissive; you can use this package freely in commercial and private projects with minimal restrictions, provided you include a copy of the license.

Quickstart:

pip install yaql

import yaql

engine = yaql.create_engine()
context = yaql.create_context()
expression = engine('$.customers.where($.age > 18)')
result = expression.evaluate(context=context, $=data)

Requires Python 3.10 or later.

Verify before relying:

- Whether the REPL and @load directive work as shown in the quickstart without additional setup.
- Current maintenance status and whether the OpenStack project is actively developing YAQL or in maintenance-only mode.
- Performance characteristics and scalability limits for large datasets or deeply nested queries.

## Package facts

- License: Apache-2.0 (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: aging
- Downloads: 317.0K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

query language for python objects, embedded query engine, json data querying, object query language, yaql query syntax, python query dsl, data filtering and transformation, query-language, data-filtering, dsl

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