Conftest.py purpose in PyTest - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Purpose of conftest.py in pytest

What is the main purpose of the conftest.py file in a pytest testing project?

A To define fixtures and hooks that can be shared across multiple test files.

B To list all test cases that pytest should run.

C To configure the Python interpreter settings for pytest.

D To store test data files used by tests.

💡 Hint

Think about how pytest shares setup code between tests.

The conftest.py file is used to define fixtures and hooks that pytest can share across multiple test files in the same directory or subdirectories. It helps avoid repeating setup code.

❓ Predict Output

intermediate

Fixture scope in conftest.py

Given this conftest.py fixture, what will be the output when running two tests that use it?

import pytest

@pytest.fixture(scope="module")
def resource():
    print("Setup resource")
    yield "resource"
    print("Teardown resource")

Two tests use this fixture in the same module.

A

Setup resource
Teardown resource
Setup resource
Teardown resource

B

Setup resource
Setup resource
Teardown resource

C

Setup resource
Setup resource
Teardown resource
Teardown resource

D

Setup resource
Teardown resource

💡 Hint

Remember what scope="module" means for fixture lifetime.

With scope="module", the fixture runs once before any tests in the module and once after all tests finish. So setup and teardown print once each.

❓ assertion

advanced

Correct fixture usage from conftest.py

Which assertion correctly tests that a fixture named db_connection from conftest.py returns a non-empty string?

A assert db_connection != None

B assert db_connection is None

C assert isinstance(db_connection, str) and len(db_connection) > 0

D assert db_connection == ''

💡 Hint

Check type and length to confirm non-empty string.

Option C checks that the fixture returns a string and that it is not empty, which is the correct way to assert a non-empty string.

🔧 Debug

advanced

Why fixture from conftest.py is not found?

You have a fixture api_client defined in conftest.py in the root tests folder. When running tests in a subfolder, pytest reports fixture 'api_client' not found. What is the most likely cause?

A The <code>conftest.py</code> file is missing an import statement for <code>api_client</code>.

B The <code>conftest.py</code> file is not in a directory recognized by pytest as a test root.

C The fixture name is misspelled in the test file.

D The subfolder has its own <code>conftest.py</code> that overrides the root one.

💡 Hint

Think about how pytest discovers conftest.py files.

Pytest discovers conftest.py files only in directories it recognizes as test roots. If the subfolder is outside or pytest is run from a different root, it won't find the fixture.

❓ framework

expert

How to share a fixture only for tests in a specific subfolder?

You want a fixture to be available only to tests inside the tests/api folder and its subfolders, but not elsewhere. How should you organize your conftest.py files?

A Place the fixture in <code>tests/api/conftest.py</code> so it applies only to that folder and below.

B Place the fixture in <code>tests/conftest.py</code> and use <code>scope='folder'</code>.

C Define the fixture in every test file inside <code>tests/api</code>.

D Place the fixture in the root <code>conftest.py</code> and add a condition to skip it outside <code>tests/api</code>.

💡 Hint

Think about how pytest applies conftest.py files based on folder location.

Pytest applies fixtures defined in a conftest.py file to tests in that folder and its subfolders. Placing the fixture in tests/api/conftest.py limits its scope correctly.