Python Validation

A python library for runtime type checking and validation of python values.

Intended as a stepping stone towards static typing.

Installation

Recommended method is to use the version from pypi

$ pip install validation

Please note that this library only supports python version 2.7, and versions 3.4 and later.

Usage

A toy example demonstrating typical usage:

from validation import (
    validate_int, validate_float,
    validate_structure,
    validate_text,
)


def function(int_arg, dict_arg, unicode_arg=None):
    """
    A normal function that expects to be called in a particular way.

    :param int int_arg:
        A non-optional integer.  Must be between one and ten.
    :param dict dict_arg:
        A dictionary containing an integer id, and a floating point amount.
    :param str unicode_arg:
        An optional string.
    """
    # Validate arguments.
    validate_int(int_arg, min_value=0, max_value=10)
    validate_structure(dict_arg, schema={
        'id': validate_int(min_value=0)
        'amount': validate_float(),
    })
    validate_text(unicode_argument, required=False)

    # Do something.
    ...

The validation functions are used to check arguments passed to a public function. Exceptions raised by the validation functions are allowed to propagate through. No logic is run until validation is complete.

Links

• Source code: https://github.com/JOIVY/validation
• Issue tracker: https://github.com/JOIVY/validation/issues
• Continuous integration: https://travis-ci.org/JOIVY/validation
• PyPI: https://pypi.python.org/pypi/validation

License

The project is made available under the terms of the Apache 2.0 license. See LICENSE for details.