Assignment: functions

As usual, clone this repo to your assignments directory (or wherever you like to work).

Python

We'll use the pytest Python library to test the functions we write below. Let's install pytest in a Python virtual environment:

python3 -m venv virtualenv         # create a python virtual environment
source ./virtualenv/bin/activate   # activate the virtual environment
pip install pytest                 # install the pytest package

1. create a new branch in your git repo called calculator

2. inside that branch create a new file called calculator.py

3. Write a program that defines four functions (multiply, add, subtract, and divide). These functions should not print anything, they should simply perform a mathematical operation on the two arguments and return the value.

4. You can test whether your functions work by running pytest in the current directory. Don't worry if you don't pass all the tests! At this step we only expect you to pass tests for add, subtract, multiply, and divide) You should ideally see something in the ouptut that looks like

    2 failed, 4 passed in 0.03s
   

5. Commit to git git commit -m "add functions to calculator"and push the change to github. git push

6. At the bottom of the file, Call the function and print a line explaining what is happening. Like this:

   print("I'm going use the calculator functions to multiply 5 and 6")
   x = multiply(5,6)
   print(x)

7. Commit this change and explain what you just did in the commit message

8. Run the file with the following command to make sure your python is all right:

   python3 calculator.py
   

9. Make sure everything works correctly and issue a pull request on github back to the main branch with a message explaining what changes you made in this branch.

10. Accept the pull request into the main branch and delete the calculator branch on github.

11. Checkout the main branch, and pull the version of main with the calculator branch merged

    git checkout main
    git pull
    

12. Delete your local version of the calculator branch

    git branch -D calculator
    

13. Create a new branch from main. In the new branch, add two more functions, square and cube. both should take a single number as an argument and return the number raised to the appropriate power.

14. Make a function called square_n_times that takes two arguments, number and n. Have the function square the number n times and return the sum.

15. PR the new branch to main. Your calcluator.py in main should now have functions for addition, subtraction, multiplication, division, squaring, cubing, and adding squares n times.

Javascript (ungraded)

Install node

On WSL: sudo apt-get install npm On Mac: brew install npm

Tasks

1. create a new branch js-calculator

2. inside that branch create a new file called calculator.js

3. Write (in javascript) a program that defines four functions (multiply, add, subtract, and divide). These functions should not print anything, they should simply perform a mathematical operation on the two arguments and return the value.

4. Commit to git git commit -m "add functions to calculator"and push the change to github. git push

5. At the bottom of the file, Call the function and print a line explaining what is happening. Like this:

   console.log("I'm going use the calculator functions to multiply 5 and 6")
   var x = multiply(5,6)
   console.log(x)

6. Commit this change and explain what you just did in the commit message

7. Run the file with the following command to make sure your JavaScript is all right:

   node calculator.js
   

8. Make sure everything works correctly and issue a pull request on github back to the main branch with a message explaining what changes you made in this branch.

9. Accept the pull request into the main branch and delete the js-calculator branch on github.

10. Checkout the main branch, and pull the version of main with the calculator branch merged

    git checkout main
    git pull
    

11. Delete your local version of the js-calculator branch

    git branch -D js-calculator