How to Pass Parameters to Pytest Test?

To pass parameters to a pytest test, you can use the pytest.mark.parametrize decorator. This decorator allows you to specify multiple sets of parameters that will be passed to the test function. The parameters are defined as arguments to the decorator, and the test function must have corresponding parameters to receive the values.

For example, you can define a test function with parameters and use the pytest.mark.parametrize decorator to pass different sets of values to the test function.pytest will automatically run the test with each set of parameters specified in the decorator.

Another way to pass parameters to a pytest test is through command-line arguments. You can use arguments passed to pytest on the command line to influence the behavior of your tests.pytest provides a way to access command-line arguments within your test functions using the request fixture.

By using either of these methods, you can pass parameters to your pytest tests and customize the behavior of your tests based on the input values.

How to pass parameters to pytest test using YAML files?

To pass parameters to pytest tests using YAML files, you can follow these steps:

1. Install the PyYAML package:

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pip install PyYAML

1. Create a YAML file with the parameters you want to pass to your tests. For example, create a file named test_params.yml:

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param1: value1
param2: value2

1. In your test file, load the YAML file and use the parameters in your test functions. For example:

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import yaml

def load_test_params():
    with open('test_params.yml', 'r') as file:
        params = yaml.safe_load(file)
    return params

def test_example():
    params = load_test_params()
    assert params['param1'] == 'value1'
    assert params['param2'] == 'value2'

1. Run your tests using pytest:

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pytest test_file.py

This way, you can pass parameters to your pytest tests using YAML files.

How to pass tuples as parameters to pytest test?

To pass tuples as parameters to a pytest test, you can use the pytest.mark.parametrize decorator. Here's an example of how you can achieve this:

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import pytest

# Define your test function
@pytest.mark.parametrize("input_tuple, expected_output", [
    ((1, 2), 3),
    ((2, 3), 5),
    ((-1, 1), 0)
])
def test_addition(input_tuple, expected_output):
    result = input_tuple[0] + input_tuple[1]
    assert result == expected_output

In this example, the @pytest.mark.parametrize decorator is used to provide test input values as tuples and expected output values. The test function test_addition takes the input tuple as a parameter and performs a addition operation on its elements. The assert statement checks if the result matches the expected output.

When you run this test using pytest, it will automatically run the test for each parameter tuple provided in the decorator.

How to pass custom objects as parameters to pytest test?

To pass custom objects as parameters to pytest test, you can use the pytest.mark.parametrize decorator along with a fixture that creates and returns the custom object. Here's an example:

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import pytest

class CustomObject:
    def __init__(self, value):
        self.value = value

@pytest.fixture
def custom_object():
    return CustomObject(42)

@pytest.mark.parametrize("custom_obj", [CustomObject(10), CustomObject(20)])
def test_custom_object(custom_obj):
    assert isinstance(custom_obj, CustomObject)
    assert custom_obj.value > 0

In this example, we define a CustomObject class and a fixture custom_object that returns an instance of the CustomObject class with a specific value. We then use the @pytest.mark.parametrize decorator to pass multiple instances of CustomObject as parameters to the test_custom_object test function.

When you run the test, pytest will automatically run the test function once for each set of parameters passed in, in this case, for each instance of CustomObject provided in the parametrize decorator.