contractme 1.1.0

A powerful, expressive and lightweight design-by-contract framework

ContractMe

A lightweight and adaptable framework for design-by-contract in python

Example code

Here are some examples:

result

@precondition(lambda x: x >= 0)
@postcondition(lambda x, result: eps_eq(result * result, x))
def square_root(x: float) -> float:
    return x**0.5

old

@precondition(lambda l, n: n >= 0 and round(n) == n)
@postcondition(lambda l, n: len(l) > 0)
@postcondition(lambda l, n: l[-1] == n)
@postcondition(lambda l, n, old: l[:-1] == old.l)
def append_count(l: list[int], n: int):
    l.append(n)

Test

uv run pytest

Changelog

• v1.1.0

Contracts can be disabled at runtime with ignore_preconditions() and ignore_postconditions()

Contracts are disabled from the start with python optimized (-O) flag.

Fix a bug where contracts would hide an incorrect function call