typing-validation

What it is and what it does

typing-validation is a runtime type checker that validates Python objects against type hints. It offers three entry points: `validate()` for one-off checks that return True or raise a detailed ValidationError; `validator()` for building a reusable checker when the same type is validated many times; and `compiled_validator()` for generating specialized Python code when validation happens at very high volume. The library reports validation failures with precise location information (e.g., which dict key or list index failed), making it useful for catching data shape problems in production code or during testing.

The package supports common type forms (list, dict, tuple, union, optional, generic classes) and rejects unsupported types upfront rather than silently passing them. It includes an extension mechanism for NumPy arrays and custom classes. No runtime dependencies means installation is friction-free. The library is actively maintained and typed throughout.

Use it for:

• Validate API request payloads or configuration dicts against a type hint before processing them.
• Check data shape in data pipelines where type mismatches indicate upstream errors.
• Gate validation behind assertions so it compiles out entirely under Python's -O flag.
• Build a fast reusable validator when the same type is checked repeatedly in a loop.
• Inspect whether a complex type is validatable before attempting validation, using can_validate().

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Runtime validation of Python objects against type hints, with three speed tiers: one-off checks, cached validators, and compiled validators optimized to near hand-written performance.

Yes, if you need runtime type validation and are on Python 3.14+. The library is actively maintained, has no dependencies, and offers a clear performance ladder (one-off, cached, compiled) for different validation frequencies. The copyleft license is a constraint in proprietary contexts but not a blocker for open-source or internal use. No known vulnerabilities.

Install

typing-validation on PyPI

pip install typing-validation

uv add typing-validation

poetry add typing-validation

Installing typing-validation

Before you install

Low friction: pure Python wheel with no runtime dependencies. Active maintenance, last release 27 days ago.

License in practice

LGPL-3.0-or-later (copyleft): derivative works and distributions must preserve the license and source availability; suitable for internal tools and open-source projects, but requires care in proprietary contexts.

Quickstart

pip install typing-validation

from typing_validation import validate, validator

# One-off check
validate([1, 2, 3], list[int])  # returns True or raises ValidationError

# Reusable validator for many values
check = validator(list[int])
check([1, 2, 3])

Requires Python 3.14 or later.

Verify before relying

• Whether the compiled_validator performance figures (23 ns per type-node) are reproducible on typical developer machines or are specific to the benchmark environment.
• Scope of NumPy array type support and whether other scientific libraries are covered by the extension mechanism.

Package facts

Evidence: typing_validation-2.2.1-py3-none-any.whl

Tags

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