The combination of Python Coverage library and unit test

The Python Coverage library is a tool for measuring code coverage. It can help developers to detect the degree of code coverage of test cases.Combined with unit testing can help us better evaluate the integrity and quality of the test, and you can find potential code errors and loopholes. To use the COVERAGE library in Python, you need to install it first.You can install the following commands in the terminal: python pip install coverage After the installation is completed, you can use the Coverage library in the project.Usually, it should be used with the unit testing framework (such as Unittest or Pytest) of the Python, so that the code coverage is automatically generated. The following is a sample code that shows how to use the COVERAGE library to cover the weight code coverage: python import unittest import coverage # Create COVERAGE object cov = coverage.Coverage() # Start collecting coverage data cov.start() # Define a simple function that will test it later def add(a, b): return a + b # Define a unit test class class TestAdd(unittest.TestCase): def test_add(self): result = add(2, 3) self.assertEqual(result, 5) # 运 运 运 运 unittest.main() # Stop collection coverage data cov.stop() # Report cov.save() cov.html_report(directory='coverage_report') In the above examples, we first introduced the Unittest and COVERAGE libraries.Then, a COVERAGE object was created and called the `start () method to start collecting coverage data.Next, a simple function `add ()` and a unit test class `testadd`.In the `Testadd` class, we wrote a test method` test_add () `to test the` add () `function.Perform the unit test by running `unittest.main ()`. After the unit test is executed, use the `COV.STOP ()` method to stop collecting the coverage data, and call the method to save the coverage data.Finally, use the method to generate the coverage report with the method of `cov.html_report ()` and save it to the specified directory. After running the above code, the test results will be displayed in the results of the run, and the code coverage report in HTML format will be generated at the same time, which is stored in a directory named `Coverage_report`. By combining the use of the COVERAGE library and unit testing framework, it can help developers to better measure the quality of the test, find unscrumable code blocks, and guide the improvement and modification of the code through the coverage report.This can improve the robustness and maintenance of the code, and reduce potential errors and defects.