Configure Hypothesis testing parameters for a test function.

Indicates that the decorated test should use extensive example generation without timeout constraints.

When you need to increase the number of generated examples for thorough property-based testing or disable timeouts for long-running tests.

Used as a decorator above a test function that uses @given or other Hypothesis decorators, typically in pytest or unittest test modules.

@settings(max_examples=<int>, deadline=None) where <int> ≥ 1

@settings(keyword_arg=value, ...) with keyword arguments max_examples and deadline

max_examples: int >= 1, deadline: float | None | datetime.timedelta

• @given
• @example
• @seed
• hypothesis

• @settings(max_examples=1000)
• @settings(deadline=datetime.timedelta(seconds=5))
• @settings(max_examples=5000
• derandomize=True)

1. Using deadline=0 (cause: misunderstanding deadline as seconds; consequence: immediate timeout causing zero examples). 2. Setting max_examples=0 (cause: thinking it means unlimited; consequence: no examples generated, test passes vacuously). 3. Forgetting to import hypothesis (cause: missing import; consequence: NameError). 4. Passing deadline as an integer instead of float/timedelta (cause: assuming seconds as int; consequence: TypeError). 5. Using deadline with a string value (cause: typo; consequence: ValueError).

@given: specifies the strategy for generating test data; @example: adds concrete example cases to the test; @seed: fixes the random seed for reproducible tests; @settings vs. Settings object: decorator vs. programmatic configuration.

Coming from unittest: may forget to import hypothesis and use @settings directly, causing NameError → import hypothesis and use @settings from hypothesis. Coming from pytest: may confuse @settings with @pytest.mark, leading to incorrect decorator usage → use @settings from hypothesis, not pytest.mark.

• @given
• @example
• @seed
• @note

1. Avoid using deadline=None in CI environments with strict time limits, as tests may hang indefinitely. 2. Setting max_examples too high can greatly increase test runtime and memory consumption. 3. The deadline=None setting disables per‑example timeouts but does not affect the overall test deadline imposed by the test runner.

Enables thorough property‑based testing without premature timeouts, increasing the chance of discovering edge‑case bugs in complex implementations.

Think of @settings as the camera settings for a property‑based test: you set the exposure (max_examples) and disable the auto‑shutter (deadline) to capture the full scene.

The deadline argument accepts a float (seconds), a datetime.timedelta object, or None to disable; max_examples controls the maximum number of generated examples before stopping.

Consider using Hypothesis profiles or a reusable Settings object for centralized configuration across multiple test modules.