is-valid 0.1.0

A small validation library.

# Is Valid? ‘Is Valid?’ is a simple lightweight python library to create validation functions that check that data is in a certain format.

## Usage There are a lot of very basic functions like is_str: `python >>> is_str("foobar") True >>> is_str(None) False ` But also more complex functions like is_match or is_list_of: `python >>> is_integer_string = is_match(r'^\d+$') >>> is_integer_string('12345') True >>> is_integer_string('12A45') False >>> is_list_of_integer_strings = is_list_of(is_integer_string) >>> is_list_of_integer_strings(['123', '456', '789']) True >>> is_list_of_integer_strings(['123', 'ABC', '789']) False >>> is_list_of_integer_strings({'123', '456', '789'}) False ` As you can see in the example above you can nest these functions very easily creating powerful validation functions that examine complex structures easily.

In some cases just True or False doesn’t cut it, you might want to know why your data is invalid. For this purpose all validation functions take a detailed keyword argument. `python >>> is_str("foobar", detailed=True) (True, None) >>> is_str(None, detailed=True) (False, 'data is not an instance of str') >>> is_integer_string('12A45', detailed=True) (False, 'data does not match /^\d+$/') >>> is_list_of_integer_strings(['123', 'ABC', '789'], detailed=True) (False, {1: 'data does not match /^\d+$/'}) >>> is_list_of_integer_strings({'123', '456', '789'}, detailed=True) (False, 'data is not an instance of list') ` You can also use this module for unittests, the module provides a mixin called IsValidMixin that you can mix in with your TestCase class to have access to self.assertIsValid(validator, data, msg=None) in your tests. If you don’t provide a message the message of your assert error will automatically be the error that the validator gives when detailed=True.

# Install ‘Is Valid?’ is on PyPi, you can install it with: ` pip install isvalid ` The module is written in pure python without any dependencies and is only a few hundred LOC.