[FEATURE] Add subtraction function

[annakrystalli]

Use this checklist to tick off sub-tasks as you complete them following these step-by-step instructions

• Create new subtract branch
• Add subtract function
• Import function in __init__.py
• Add subtract test
• Commit changes and push to GitHub
• Make pull request
• Close issue

Instructions

Create branch

Create a new subtract branch from main to work in.

Add subtraction function

Create a new subtract.py file in the pythoncalculator/ directory.

def subtract(x, y)
    return x - y

Open the pythoncalculator/__init__.py file and add the following line of code:

from .subtract import subtract 

Add subtraction test

Create a new test_subtract.py file in the tests/ directory.

Add the following code and save:

from pythoncalculator import subtract


def test_subtract():
    assert subtract(1, 3) == -2

Commit your changes and push to GitHub

Once you've created your function and test files and added the line to import your function to pythoncalculator/__init__.py, commit your changes.

Use resolves #{ISSUE_NUMBER_YOU_WERE_ASSIGNED} in your commit message to automatically close the issue when your pull request is merged.

Then push them up to GitHub

Create pull request

Finally, create a pull request back to the main branch on GitHub and wait for the owner's review.

Reference the issue your pull request refers to with #{ISSUE_NUMBER_YOU_WERE_ASSIGNED} in the description.

Respond to any requests for correction.

Close issue

If the issue didn't close automatically, close it yourself. You can also