Test functions in PyTest - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a test function in pytest?

A test function in pytest is a regular Python function whose name starts with test_. It contains code to check if a part of your program works correctly.

beginner

How do you write a simple test function to check if 2 + 2 equals 4?

You write a function starting with test_ and use an assert statement like this:<br>

def test_addition():
    assert 2 + 2 == 4

intermediate

Why should test functions be independent?

Test functions should be independent so that one test's result does not affect another. This makes tests reliable and easier to debug.

beginner

What happens if an assertion in a test function fails?

If an assertion fails, pytest marks the test as failed and shows an error message explaining what went wrong.

beginner

How does pytest find test functions to run?

Pytest automatically finds functions that start with test_ in files named test_*.py or *_test.py.

What prefix should a function name have to be recognized as a test by pytest?

A check_

B test_

C verify_

D run_

Pytest recognizes functions starting with test_ as test functions.

What keyword is used inside a test function to check if a condition is true?

A assert

B check

C verify

D test

The assert keyword is used to verify conditions in test functions.

If a test function's assertion fails, what will pytest report?

A Test passed

B Test skipped

C Test failed

D Test ignored

Pytest reports the test as failed if an assertion inside it fails.

Which file name pattern does pytest use to find test files?

A test_*.py

B run_*.py

C check_*.py

D verify_*.py

Pytest looks for files named test_*.py or *_test.py to find tests.

Why is it important that test functions do not depend on each other?

A To make tests run faster

B To reduce code size

C To use less memory

D To avoid test failures caused by other tests

Independent tests avoid failures caused by side effects from other tests.

Explain how to write a basic test function in pytest and what it should contain.

Think about a simple function that checks if something is true.

Describe why test functions should be independent and how pytest finds them.

Consider reliability and automatic test discovery.