I denna utmaning kommer du att tillämpa din förståelse av Pythons testningsramverk genom att implementera och testa en enkel kalkylatorklass. Din kalkylator ska stödja fyra grundläggande operationer: addition, subtraktion, multiplikation och division. Du kommer att använda ramverket `unittest` för att skriva omfattande tester som verifierar korrektheten för varje operation.

Kom ihåg att utforma dina tester så att varje metod i kalkylatorn täcks, inklusive kontroller för normal funktion och för gränsfall som division med noll.


import unittest
import user_code
import ast
import re   
import importlib
import csv
import unittest
import importlib

class TestTask(unittest.TestCase):
    def setUp(self):
        self.user_code = importlib.import_module("user_code")
        importlib.reload(self.user_code)
        self.Calc = getattr(self.user_code, "Calculator", None)

    def test_add_positive_and_negative(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.add(2, 3) == 5 and calc.add(-2, -3) == -5,
            "Add method returns correct sums for positive and negative integers",
            f"Add method failed: got {calc.add(2,3)} for (2,3), {calc.add(-2,-3)} for (-2,-3)",
        )

    def test_subtract_positive_and_negative(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.subtract(5, 3) == 2 and calc.subtract(-2, -3) == 1,
            "Subtract method returns correct results for positive and negative integers",
            f"Subtract method failed: got {calc.subtract(5,3)} for (5,3), {calc.subtract(-2,-3)} for (-2,-3)",
        )

    def test_multiply_positive_and_zero(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.multiply(4, 3) == 12 and calc.multiply(0, 5) == 0,
            "Multiply method returns correct product for positive integers and zero",
            f"Multiply method failed: got {calc.multiply(4,3)} for (4,3), {calc.multiply(0,5)} for (0,5)",
        )

    def test_divide_integer_and_float(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.divide(10, 2) == 5 and calc.divide(7, 2) == 3.5,
            "Divide method returns correct quotient for integer and floating-point division",
            f"Divide method failed: got {calc.divide(10,2)} for (10,2), {calc.divide(7,2)} for (7,2)",
        )

    def test_divide_by_zero(self):
        calc = self.Calc()
        try:
            calc.divide(5, 0)
            _dynamic_test(
                self,
                False,
                "Divide method raises ZeroDivisionError when dividing by zero",
                "Divide method did not raise ZeroDivisionError when dividing by zero",
            )
        except ZeroDivisionError:
            _dynamic_test(
                self,
                True,
                "Divide method raises ZeroDivisionError when dividing by zero",
                "Divide method did not raise ZeroDivisionError when dividing by zero",
            )

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):
    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:
    tree = ast.parse(code)
    lines = code.splitlines()
    changed = False
    # Collect all assignment nodes to modify
    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 nothing to change, return unmodified code
    if not assign_nodes:
        return code

    # Perform replacements for all matching assignments (from last to first to not break line offsets)
    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

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


test_main.py

Du kommer att förvärva praktiska färdigheter i Pythons moduler och importer för effektiv kodhantering. Behärska avancerade tekniker för felhantering för mer tillförlitliga applikationer, automatisera filoperationer med filhantering och lär dig robusta teststrategier med Pytest och Unittest för att säkerställa kodens integritet.

Master Python's exception system for robust error handling and debugging.

Explore advanced techniques for file operations and resource management using context managers.

Compare and apply Python's multithreading and multiprocessing modules for concurrent programming.

Master asynchronous programming in Python using the asyncio library for scalable I/O-bound applications.

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Utmaning: Testa en Kalkylatorklass

Lösning