In deze uitdaging pas je je kennis van Python's **threading**-concepten toe om een drukke koffiewinkel te simuleren. De opdracht is om een programma te schrijven dat meerdere koffieorders gelijktijdig bereidt met behulp van threads. Je maakt gebruik van **parallelle uitvoering**, waarbij je verwijst naar de concepten van **threadbeheer** die je in het vorige hoofdstuk hebt geleerd. Deze uitdaging helpt je om het gebruik van **multithreading** voor het gelijktijdig afhandelen van meerdere taken te versterken en zorgt voor een goede coördinatie door het samenvoegen van threads.

import unittest
import user_code
import importlib
import io
import sys
import time

class TestTask(unittest.TestCase):
    def test_brew_coffee_prints_message(self):
        importlib.reload(user_code)
        f = io.StringIO()
        sys_stdout = sys.stdout
        sys.stdout = f
        try:
            user_code.brew_coffee("Mocha")
        finally:
            sys.stdout = sys_stdout
        output = normalize_text(f.getvalue())
        expected = normalize_text("Mocha is ready!")
        _dynamic_test(
            self,
            expected in output,
            "brew_coffee prints correct ready message",
            f"Expected output '{expected}' not found in '{output}'",
        )

    def test_brew_all_coffees_starts_threads_and_joins(self):
        importlib.reload(user_code)
        orders = ["Americano", "Flat White", "Macchiato"]
        f = io.StringIO()
        sys_stdout = sys.stdout
        sys.stdout = f
        start = time.time()
        try:
            user_code.brew_all_coffees(orders)
        finally:
            sys.stdout = sys_stdout
        elapsed = time.time() - start
        output = normalize_text(f.getvalue())
        for order in orders:
            expected = normalize_text(f"{order} is ready!")
            _dynamic_test(
                self,
                expected in output,
                f"Output contains ready message for {order}",
                f"Expected ready message for '{order}' not found in output: '{output}'",
            )
        _dynamic_test(
            self,
            elapsed >= 0.2 and elapsed < 0.5,
            "brew_all_coffees runs in parallel (not sequentially)",
            f"brew_all_coffees did not run in parallel. Elapsed: {elapsed}",
        )

    def test_brew_all_coffees_handles_empty_orders(self):
        importlib.reload(user_code)
        orders = []
        f = io.StringIO()
        sys_stdout = sys.stdout
        sys.stdout = f
        try:
            user_code.brew_all_coffees(orders)
        finally:
            sys.stdout = sys_stdout
        output = f.getvalue().strip()
        _dynamic_test(
            self,
            output == "",
            "No output when orders is empty",
            f"Expected no output, got: '{output}'",
        )

    def test_brew_coffee_sleep_time(self):
        importlib.reload(user_code)
        start = time.time()
        user_code.brew_coffee("TestCoffee")
        elapsed = time.time() - start
        _dynamic_test(
            self,
            elapsed >= 0.19,
            "brew_coffee sleeps for at least 0.2 seconds",
            f"brew_coffee did not sleep long enough. Elapsed: {elapsed}",
        )

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 normalize_text(text):
    import re
    text = text.lower()
    text = re.sub(r"\\s{2,}", " ", text)
    text = re.sub(r"\\s*([,:?])\\s*", r"\\1 ", text)
    return text.strip()

def change_var(code: str, var_name: str, value: str) -> str:
    import ast
    tree = ast.parse(code)
    lines = code.splitlines()
    changed = False
    assign_nodes = [
        (i, node)
        for i, node in enumerate(tree.body)
        if isinstance(node, ast.Assign)
        and any(isinstance(target, ast.Name) and target.id == var_name for target in node.targets)
    ]
    if not assign_nodes:
        return code
    for i, node in reversed(assign_nodes):
        start_line = node.lineno - 1
        line = lines[start_line]
        indent = ' ' * (len(line) - len(line.lstrip()))
        lines[start_line] = f"{indent}{var_name} = {value}"
        next_line = len(lines)
        for next_node in tree.body[i+1:]:
            if hasattr(next_node, 'lineno'):
                next_line = next_node.lineno - 1
                break
        if next_line > start_line + 1:
            lines[start_line+1:next_line] = []
        changed = True
    return '\\n'.join(lines) if changed else code


test_main.py

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Uitdaging: Parallelle Bestandsverwerking

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