Project structure for tests in PyTest - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Why use a separate tests directory in pytest projects?

In pytest projects, why is it recommended to keep all test files inside a separate tests/ directory?

A To organize tests separately from application code for clarity and easier test discovery.

B Because pytest only runs tests inside a folder named <code>tests</code>.

C To prevent tests from being included in the final application package automatically.

D To make test files hidden from version control systems like Git.

💡 Hint

Think about how separating concerns helps in managing code.

Keeping tests in a dedicated tests/ folder helps keep the project organized. It separates test code from application code, making it easier to find and run tests. Pytest can discover tests in any folder, but tests/ is a common convention.

❓ Predict Output

intermediate

What is the output when running pytest with this structure?

Given this project structure:

my_project/
  app.py
  tests/
    test_math.py
    test_utils.py

And test_math.py contains a passing test, what will pytest report when run from my_project/?

PyTest

def test_addition():
    assert 1 + 1 == 2

A pytest will not find any tests because they are inside a subfolder.

B pytest will run tests but report failures due to missing __init__.py files.

C pytest will raise an error because test files must be in the root folder.

D pytest will find and run the test, reporting 1 passed test.

💡 Hint

Pytest automatically finds tests in subfolders named test_*.py.

Pytest recursively searches for test files matching test_*.py or *_test.py patterns. It will find test_math.py inside tests/ and run the test, reporting success.

❓ locator

advanced

Best locator for a test file in pytest project

Which filename is the best practice locator for a pytest test file that tests user authentication?

A test_authentication.py

B authentication_test.py

C authTests.py

D TestAuthentication.py

💡 Hint

Pytest looks for files starting with test_ or ending with _test.py.

By convention, pytest test files start with test_ or end with _test.py. test_authentication.py follows this and uses lowercase with underscores, which is recommended.

❓ assertion

advanced

Which assertion correctly checks a list length in pytest?

You want to assert that a list items has exactly 3 elements in a pytest test. Which assertion is correct and best practice?

PyTest

items = [1, 2, 3]

A assert items.count == 3

B assert items.length == 3

C assert len(items) == 3

D assert items.size() == 3

💡 Hint

Remember how to get the length of a list in Python.

In Python, len() returns the number of elements in a list. The other options use invalid syntax or methods not available on lists.

❓ framework

expert

How to structure pytest fixtures for reusable setup?

You want to create a reusable setup for database connection in pytest tests. Which project structure and fixture placement is best practice?

A Define the fixture inside each test file that needs it to avoid global scope.

B Place the fixture in <code>tests/conftest.py</code> so all tests can use it without imports.

C Put the fixture in the main application code folder to share with non-test code.

D Create a separate <code>fixtures.py</code> file inside <code>tests/</code> and import it in each test file.

💡 Hint

Think about how pytest discovers fixtures automatically.

Placing fixtures in conftest.py inside the tests/ folder allows pytest to find them automatically for all tests in that folder and subfolders without explicit imports. This promotes reuse and cleaner test files.