How Do You Write a Unit Test in Python?

We can use the following frameworks provided by Python's inbuilt API for writing unit test cases in Python language:

1. unittest

Below are the steps to write a test case with the unittest module:

• Import the unitest module i.e. inbuilt module of python library
• Write a class that will inherit the unittest.TestCase class
• Test method must prefix by the string ‘test’
• Run the test class and test methods by unittest.main()

2. pytest

Below are the steps to write the test case with pytest module:

• Must start your class name with ‘test’ word
• Run your python file on the command line with pytest <pythonfile_name.py>

The pytest is the most recommended framework, since pytest also provides some extra features as compared to the unittest module. Some of these features are:

• Its fixtures provide a better approach for setup and teardown methods(@pytest.usefixtures)
• It provides parameterization of data for test methods (@mark.parameterize)
• It provides markers for grouping the test methods (@pytest.mark.<groupname>)

Note: There is no need to import the unittest module or inherit the unittest. TestCase is in pytest module.