In this practice, you will write Python code to make a series of unit tests pass.

1. Clone the repository.
2. Change directory into the repository.
3. Make sure you are running a version of Python 3.9.
4. Install the Pipfile by running pipenv install.
5. Run pytest to run the tests.

1. Manually test by running the file (for example, python problem_01_list.py). Before you run all the unit tests, use manual testing to compare your result with the expected result commented next to the print statements.
2. Run the tests by typing pytest.
3. Your objective is to implement the code in each of the following Python modules so that when you run pytest, all tests pass. A green dot (.) next to the tests means that it passed a test.

1. There are two __pycache__ directories, one in the root of your project and one in the test subdirectory. Delete both of those __pycache__ directories.
2. ZIP your project directory.
3. Submit it using the submit button.