Unittest practice with arithmetic functions

test_simple_calculator.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Unittest practice
This program does basic arithmetic and provides a test class to test it.

# Running
python3 -m unittest test_simple_calculator.py
"""
import unittest


def add(arg1, arg2):
    """Return the sum of two numbers"""
    return arg1 + arg2


def subtract(arg1, arg2):
    """Return the difference of two numbers"""
    return arg1 - arg2


def multiply(arg1, arg2):
    """Return the product of two numbers"""
    return arg1 * arg2


def divide(arg1, arg2):
    """Return the quotient of two numbers"""
    return arg1 / arg2


class TestSimpleCalculator(unittest.TestCase):
    """Test simple calculator functions."""
    def test_add_positives(self):
        self.assertEqual(add(2, 1), 3)

    def test_add_negatives(self):
        self.assertEqual(add(-2, -1), -3)

    def test_subtract_positives(self):
        self.assertEqual(subtract(2, 1), 1)

    def test_subtract_negatives(self):
        self.assertEqual(subtract(-2, -1), -1)

    def test_multiply_positives(self):
        self.assertEqual(multiply(2, 1), 2)

    def test_multiply_negatives(self):
        self.assertEqual(multiply(-2, -1), 2)

    def test_divide_positives(self):
        self.assertEqual(multiply(2, 1), 2)

    def test_divide_negatives(self):
        self.assertEqual(multiply(-2, -1), 2)