Parametrized fixtures in PyTest - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a parametrized fixture in pytest?

A parametrized fixture is a fixture that runs multiple times with different input values, allowing tests to reuse setup code with various data.

beginner

How do you define a parametrized fixture in pytest?

Use the @pytest.fixture decorator with the 'params' argument listing values. pytest runs the fixture once for each value.

beginner

Example: What does this fixture do?

@pytest.fixture(params=[1, 2, 3])
def number(request):
    return request.param

It creates a fixture named 'number' that will provide values 1, 2, and 3 to tests, running each test three times with these values.

intermediate

Why use parametrized fixtures instead of multiple test functions?

Parametrized fixtures reduce code duplication and keep tests clean by reusing setup logic with different inputs automatically.

beginner

How can you access the current parameter value inside a parametrized fixture?

Use 'request.param' inside the fixture function to get the current parameter value.

What does the 'params' argument in @pytest.fixture do?

A Runs the fixture multiple times with each value in the list

B Skips the fixture

C Runs the fixture only once

D Marks the fixture as private

The 'params' argument tells pytest to run the fixture once for each value provided.

How do you get the current parameter value inside a parametrized fixture?

A Using 'param.value'

B Using 'self.param'

C Using 'fixture.param'

D Using 'request.param'

Inside the fixture, 'request.param' holds the current parameter value.

If a fixture is parametrized with 3 values, how many times will a test using it run?

A 1

B Depends on test count

C 3

D 0

The test runs once for each parameter value, so 3 times.

Which decorator is used to create a parametrized fixture?

A @pytest.run

B @pytest.fixture(params=[...])

C @pytest.test

D @pytest.parametrize

Parametrized fixtures use @pytest.fixture with the 'params' argument.

What is a benefit of parametrized fixtures?

A They reduce code duplication

B They slow down tests

C They hide test failures

D They disable tests

Parametrized fixtures help reuse setup code and avoid repeating similar tests.

Explain how to create and use a parametrized fixture in pytest.

Think about how pytest runs tests multiple times with different data.

Describe the advantages of using parametrized fixtures over writing multiple test functions.

Consider how setup code can be reused.