Addopts for default options in PyTest

Introduction

Addopts lets you set default command-line options for pytest. This saves time by not typing options every time you run tests.

You want pytest to always show detailed test results without typing -v each time.

You want to run tests with a specific marker by default.

You want to set a default timeout for all tests.

You want to always generate a test report file automatically.

You want to ignore certain warnings every time you run tests.

Syntax

PyTest

[pytest]
addopts = <options>

Put this in a pytest.ini file in your project root.

Options are the same as you type on the command line.

Examples

This makes pytest always run in verbose mode, showing each test name.

PyTest

[pytest]
addopts = -v

This runs only tests marked with @pytest.mark.smoke by default.

PyTest

[pytest]
addopts = -m smoke

This stops after 2 failures and hides warnings automatically.

PyTest

[pytest]
addopts = --maxfail=2 --disable-warnings

Sample Program

This config runs pytest in verbose mode and stops after 1 failure. The sample tests include one passing, one failing, and one skipped test.

PyTest

[pytest]
addopts = -v --maxfail=1

# test_sample.py
import pytest

def test_pass():
    assert 1 == 1

def test_fail():
    assert 1 == 2

def test_skip():
    pytest.skip('skip this test')

Important Notes

You can combine multiple options in addopts separated by spaces.

If you want to override addopts options, you can still pass options directly on the command line.

Use pytest --help to see all available options you can add.

Summary

Addopts sets default pytest command-line options in pytest.ini.

This saves time and ensures consistent test runs.

Options are the same as typing them manually when running pytest.

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