Let's put together everything you've learned in this section and apply it.

In this task, your objective is to calculate the **total revenue for each product** in a grocery store based on their prices and quantities sold. 

After calculating the revenues, you will **sort the products alphabetically** and **display the results** in a formatted output.

import unittest
import importlib
import io
import re
import inspect
from contextlib import redirect_stdout
import user_code


def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)


def strip_comments_from_source(module):
    try:
        source = inspect.getsource(module)
        lines = source.split('\\n')
        cleaned = []
        for line in lines:
            stripped = line.rstrip()
            if stripped.startswith('#'):
                continue
            if '#' in line:
                line = line.split('#')[0]
            if line.strip():
                cleaned.append(line)
        return '\\n'.join(cleaned)
    except Exception:
        return ""


class TestRevenueFunctions(unittest.TestCase):

    def normalize_text(self, text):
        text = text.lower()
        text = re.sub(r'\s+', ' ', text)
        text = re.sub(r'\s*([,:?\[\]$])\s*', r'\1', text)
        return text.strip()

    def test_calculate_revenue_works(self):
        importlib.reload(user_code)
        prices = [1.0, 2.0, 3.0]
        quantities = [10, 20, 30]
        expected = [10.0, 40.0, 90.0]
        result = user_code.calculate_revenue(prices, quantities)
        _dynamic_test(
            self,
            result == expected,
            "calculate_revenue returns correct result for sample input",
            f"Expected {expected}, got {result}"
        )

    def test_function_names_exist(self):
        importlib.reload(user_code)
        _dynamic_test(self, hasattr(user_code, "calculate_revenue"), "Function 'calculate_revenue' exists", "Function 'calculate_revenue' not found")
        _dynamic_test(self, hasattr(user_code, "formatted_output"), "Function 'formatted_output' exists", "Function 'formatted_output' not found")

    def test_revenue_combined_and_sorted(self):
        importlib.reload(user_code)
        expected_sorted = [
            ("Apples", 240.0),
            ("Bananas", 100.0),
            ("Bread", 75.0),
            ("Oranges", 250.0)
        ]
        sorted_output = sorted(user_code.revenue_per_product)
        _dynamic_test(
            self,
            sorted_output == expected_sorted,
            "Revenue per product is correctly zipped and sorted",
            f"Expected sorted result: {expected_sorted}, got {sorted_output}"
        )

    def test_output_format_correct(self):
        f = io.StringIO()
        with redirect_stdout(f):
            importlib.reload(user_code)
        output = self.normalize_text(f.getvalue())

        expected_lines = [
            "apples has total revenue of $240.0",
            "bananas has total revenue of $100.0",
            "bread has total revenue of $75.0",
            "oranges has total revenue of $250.0"
        ]

        for line in expected_lines:
            expected = self.normalize_text(line)
            _dynamic_test(
                self,
                expected in output,
                f"Output includes: {line}",
                f"Expected output: '{line}' not found."
            )


if __name__ == '__main__':
    unittest.main()

test_main.py

Python is a high-level, interpreted, general-purpose programming
language. Distinguished from languages such as HTML, CSS, and JavaScript, which are mainly
utilized in web development, Python boasts versatility across multiple domains, including
software development, data science, and back-end development. This course will guide you
through Python's fundamental concepts, equipping you with the skills to create your own
functions by the conclusion of the program.

In this section, you will explore the fundamentals of Python, get acquainted
with your workspace, perform simple math operations, and display your findings.

In this section, you'll discover how to save items such as numbers and text
in computer memory and retrieve them by name. Additionally, you'll gain an introduction to text
manipulation in Python.

In this section, you'll explore the boolean data type and learn how it is used
to develop programs that react to certain conditions.

In this section, you will continue learning about data types and discover
how to organize various attributes in a single variable using lists, tuples, and dictionaries.

In this section, you'll learn how to create loops in Python — an essential skill
for iterating through lists, tuples, and dictionaries.

To conclude this introductory course, you will explore some built-in
functions and then begin to develop your own!

Challenge: Product Revenues Capstone

Solution