How to Mock Environment Variables in Python Tests with Pytest

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How to Mock Environment Variables in Python Tests with Pytest

The Problem at Hand

Consider a scenario where you have two files:

Here’s a quick look at the code structure:

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Steps to Implement:

Set the Environment Variable: Before your tests run, define the environment variable you need.

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Explanation:

Fixture: By using a pytest fixture, you can automatically set up the environment variable before every test that’s run.

Yield Statement: After setting the environment variable, we yield control. This means the test will execute with the environment variable defined.

Cleanup: After the test finishes running, we delete the environment variable to ensure that it doesn't affect other tests.

Running Your Tests

Benefits of This Approach:

Isolation: This method keeps your tests isolated and reduces dependencies on external conditions (like actual environment variables).

Clean Code: There’s no need for unnecessary mockery or alterations of production code.

Conclusion

Remember, effective testing practices not only improve your code quality but also enhance your overall development workflow. Happy testing!