Deal -- python library for design by contract (DbC) programming. That's nice assert statements in decorators style to validate function input, output, available operations and object state. Goal is make testing much easier and detect errors in your code that occasionally was missed in tests.
Deal alternatives and similar packages
Based on the "Functional Programming" category.
Alternatively, view Deal alternatives based on common mentions on social networks and blogs.
4.2 0.0 L4 Deal VS CyToolzCython implementation of Toolz: High performance functional utilities
* Code Quality Rankings and insights are calculated and provided by Lumnify.
They vary from L1 to L5 with "L5" being the highest.
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- Classic DbC: precondition, postcondition, invariant.
- Tracking exceptions and side-effects.
- Property-based testing.
- Static checker.
- Integration with pytest, flake8, and hypothesis.
- Type annotations support.
- External validators support.
- Contracts for importing modules.
- Can be enabled or disabled on production.
- [Colorless](colorless): annotate only what you want. Hence, easy integration into an existing project.
- Colorful: syntax highlighting for every piece of code in every command.
- Memory leaks detection: deal makes sure that pure functions don't leave unexpected objects in the memory.
- DRY: test discovery, error messages generation.
- Partial execution: linter executes contracts to statically check possible values.
- Formal verification: prove that your code works for all input (or find out when it doesn't).
Deal in 30 seconds
# the result is always non-negative @deal.post(lambda result: result >= 0) # the function has no side-effects @deal.pure def count(items: List[str], item: str) -> int: return items.count(item) # generate test function test_count = deal.cases(count)
Now we can:
python3 -m deal lintor
flake8to statically check errors.
python3 -m deal testor
pytestto generate and run tests.
- Just use the function in the project and check errors in runtime.
Read more in the documentation.
python3 -m pip install --user deal
Contributions are welcome! A few ideas what you can contribute:
- Add new checks for the linter.
- Improve documentation.
- Add more tests.
- Improve performance.
- Found a bug? Fix it!
- Made an article about deal? Great! Let's add it into the
- Don't have time to code? No worries! Just tell your friends and subscribers about the project. More users -> more contributors -> more cool features.
Thank you :heart: