https://github.com/wemake-services/safe-assert

Safe and composable assert for Python that can be used together with optimised mode
https://github.com/wemake-services/safe-assert

assert mypy mypy-stubs pep561 python python3 type-safety utility

Last synced: 3 months ago
JSON representation

Safe and composable assert for Python that can be used together with optimised mode

• Host: GitHub
• URL: https://github.com/wemake-services/safe-assert
• Owner: wemake-services
• License: mit
• Created: 2019-10-25T22:15:01.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2024-04-12T07:08:58.000Z (10 months ago)
• Last Synced: 2024-04-14T04:07:23.806Z (9 months ago)
• Topics: assert, mypy, mypy-stubs, pep561, python, python3, type-safety, utility
• Language: Python
• Homepage: https://pypi.org/project/safe-assert/
• Size: 361 KB
• Stars: 16
• Watchers: 3
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# safe-assert

[![wemake.services](https://img.shields.io/badge/%20-wemake.services-green.svg?label=%20&logo=data%3Aimage%2Fpng%3Bbase64%2CiVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAMAAAAoLQ9TAAAABGdBTUEAALGPC%2FxhBQAAAAFzUkdCAK7OHOkAAAAbUExURQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP%2F%2F%2F5TvxDIAAAAIdFJOUwAjRA8xXANAL%2Bv0SAAAADNJREFUGNNjYCAIOJjRBdBFWMkVQeGzcHAwksJnAPPZGOGAASzPzAEHEGVsLExQwE7YswCb7AFZSF3bbAAAAABJRU5ErkJggg%3D%3D)](https://wemake.services)

[![test](https://github.com/wemake-services/safe-assert/workflows/test/badge.svg?branch=master&event=push)](https://github.com/wemake-services/safe-assert/actions?query=workflow%3Atest)

[![codecov](https://codecov.io/gh/wemake-services/safe-assert/branch/master/graph/badge.svg)](https://codecov.io/gh/wemake-services/safe-assert)

[![Python Version](https://img.shields.io/pypi/pyversions/safe-assert.svg)](https://pypi.org/project/safe-assert/)

[![wemake-python-styleguide](https://img.shields.io/badge/style-wemake-000000.svg)](https://github.com/wemake-services/wemake-python-styleguide)

Allows users to write composable `assert`s that are not stripped away in [optimized mode](https://docs.python.org/3/using/cmdline.html#cmdoption-o).

## Features

- Single simple, pythonic, fast, tested, typed, documented function. That's it!

- Because `safe_assert` is a function, it can be easily composed with other functions

- Fully typed with annotations and checked with mypy, [PEP561 compatible](https://www.python.org/dev/peps/pep-0561/)

## Installation

```bash

pip install safe-assert

```

## Examples

The usage is identical to `assert` keyword, but a function:

```python

from safe_assert import safe_assert

def sort_positive_numbers(numbers: List[int]) -> List[int]:

    safe_assert(all(num >= 0 for num in numbers), 'found negative')

    return sorted(numbers)

sort_positive_numbers([1, 2, 3])  # => will work

sort_positive_numbers([-1, 2, 3])

# => will fail in runtime with `AssertionError`

```

How is it different from regular `assert`?

The major one is that it would not be stripped away with `-O` flag.

So, it still allows to write declarative checks that are safe in production.

The second one is that you can compose it as any other regular function.

Useful in conjunction with [`dry-python`](https://github.com/dry-python) projects.

## Internals

How does it work internally?

It internally raises [`AssertionError`](https://docs.python.org/3/library/exceptions.html#AssertionError) that is also used by the `assert` keyword itself.

See [docs](https://github.com/wemake-services/safe-assert/blob/master/safe_assert/__init__.py) to learn more.

## License

MIT.