Addopts for default options in PyTest - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the addopts setting in pytest?

The addopts setting in pytest allows you to specify default command-line options that pytest will use every time it runs. This helps avoid typing common options repeatedly.

beginner

Where do you add the addopts setting to configure default pytest options?

You add the addopts setting in the pytest.ini file or other pytest configuration files like tox.ini or setup.cfg.

beginner

Example: How to set pytest to always show detailed test output by default using addopts?

In pytest.ini, add:

[pytest]
addopts = -v

This makes pytest run with verbose output every time without typing -v.

intermediate

Can command-line options override addopts settings?

Yes. Options given directly on the command line when running pytest will override the defaults set in addopts.

intermediate

Why is using addopts helpful in a team environment?

Using addopts ensures everyone runs pytest with the same default options, leading to consistent test runs and easier debugging.

Where is the addopts setting typically placed to set default pytest options?

A In the <code>pytest.ini</code> file

B Inside each test function

C In the Python environment variables

D In the test script comments

The addopts setting is placed in configuration files like pytest.ini to apply default options globally.

What happens if you run pytest with a command-line option that conflicts with addopts?

A <code>addopts</code> always overrides command-line options

B Both options are ignored

C pytest throws an error

D The command-line option overrides <code>addopts</code>

Command-line options have higher priority and override the defaults set in addopts.

Which of these is a valid use of addopts in pytest.ini?

A [pytest] addopts = import pytest

B [pytest] addopts = test_function()

C [pytest] addopts = -v --maxfail=2

D [pytest] addopts = def test(): pass

Option C correctly sets default command-line options for pytest in the config file.

Why might you want to use addopts instead of typing options every time?

A To ensure consistent test runs and save time

B To make tests run slower

C To disable all tests

D To avoid writing test code

addopts helps run tests consistently and saves typing effort.

Which file can also contain addopts besides pytest.ini?

A requirements.txt

B tox.ini

C README.md

D setup.py

tox.ini can include pytest configuration including addopts.

Explain how to use addopts to set default pytest options and why it is useful.

Think about how to save time and keep test runs consistent.

Describe a scenario where using addopts improves teamwork in testing.

Consider how shared settings help a team.

Practice

1. What is the main purpose of the addopts setting in a pytest.ini file?

easy

A. To set default command-line options for pytest runs

B. To define test case names automatically

C. To specify the Python version for pytest

D. To list all test files explicitly

Solution

1. Step 1: Understand addopts role in pytest.ini

   addopts is used to provide default command-line options so you don't have to type them every time.

2. Step 2: Compare other options

   Other options like naming tests or Python version are not controlled by addopts.

3. Final Answer:

   To set default command-line options for pytest runs -> Option A

4. Quick Check:

   Default pytest options = addopts [OK]

Hint: Remember: addopts sets default pytest command options [OK]

Common Mistakes:

• Thinking addopts defines test names
• Confusing addopts with Python version settings
• Assuming addopts lists test files

2. Which of the following is the correct way to add default options in pytest.ini using addopts?

easy

A. [pytest]
addopts = maxfail=3 verbose

B. [pytest]
addopts: --maxfail=3 --verbose

C. [pytest]
addopts = --maxfail=3 --verbose

D. [pytest]
addopts --maxfail=3 --verbose

Solution

1. Step 1: Check correct syntax for ini files

   In pytest.ini, options are set as key = value pairs under [pytest] section.

2. Step 2: Validate option format

   Options must be space-separated strings with dashes, e.g., --maxfail=3 --verbose.

3. Final Answer:

   [pytest]\naddopts = --maxfail=3 --verbose -> Option C

4. Quick Check:

   Ini syntax uses = and spaces for addopts [OK]

Hint: Use '=' after addopts and space-separated options [OK]

Common Mistakes:

• Using ':' instead of '='
• Omitting dashes before options
• Not placing options under [pytest] section

3. Given this pytest.ini content:

[pytest]
addopts = --maxfail=2 --tb=short

What will happen when you run pytest tests/ without extra options?

medium

A. Pytest runs all tests and shows full tracebacks

B. Pytest stops after 2 failures and shows short tracebacks

C. Pytest ignores addopts and runs normally

D. Pytest throws a syntax error due to addopts

Solution

1. Step 1: Understand addopts effect on pytest run

   The options --maxfail=2 and --tb=short set limits on failures and traceback style by default.

2. Step 2: Predict behavior without extra command-line options

   Since addopts sets defaults, pytest will stop after 2 failures and show short tracebacks automatically.

3. Final Answer:

   Pytest stops after 2 failures and shows short tracebacks -> Option B

4. Quick Check:

   addopts options apply by default [OK]

Hint: Default options run automatically without typing them [OK]

Common Mistakes:

• Assuming addopts is ignored
• Thinking full tracebacks show by default
• Expecting all tests to run despite maxfail

4. You added addopts = --maxfail=1 --verbose to pytest.ini but pytest still runs all tests without stopping early. What is the likely cause?

medium

A. The pytest.ini file is not in the current directory or pytest root

B. The --maxfail option does not work with addopts

C. You must run pytest with --use-addopts flag

D. Verbose mode disables maxfail stopping

Solution

1. Step 1: Check pytest.ini location

   Pytest only reads pytest.ini if it is in the current directory or a parent directory of the test run.

2. Step 2: Understand addopts behavior

   If pytest.ini is misplaced, addopts settings are ignored and default pytest behavior occurs.

3. Final Answer:

   The pytest.ini file is not in the current directory or pytest root -> Option A

4. Quick Check:

   pytest.ini location affects addopts usage [OK]

Hint: Ensure pytest.ini is in the test root folder [OK]

Common Mistakes:

• Believing maxfail needs special flags
• Thinking verbose disables maxfail
• Ignoring pytest.ini file location

5. You want pytest to always run tests with coverage report and stop after 5 failures by default. Which addopts line in pytest.ini achieves this correctly?

hard

A. [pytest]
addopts: --cov src --maxfail=5

B. [pytest]
addopts = maxfail=5 --cov src

C. [pytest]
addopts = --maxfail=5 --cov=src --stop

D. [pytest]
addopts = --cov=src --maxfail=5

Solution

1. Step 1: Understand correct option syntax

   Coverage option requires --cov=src with equals sign; maxfail uses --maxfail=5.

2. Step 2: Check for invalid or missing syntax

   Options without '=' or extra unknown flags like --stop are incorrect.

3. Final Answer:

   [pytest]\naddopts = --cov=src --maxfail=5 -> Option D

4. Quick Check:

   Use '=' for options with values in addopts [OK]

Hint: Use '=' for options with values like --cov=src [OK]

Common Mistakes:

• Omitting '=' in options with values
• Adding unsupported flags like --stop
• Switching order without '=' causing errors