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

class TestTask(unittest.TestCase):

    def test_instance_increments_total_users(self):
        import user_code
        importlib.reload(user_code)
        cls = getattr(user_code, 'User', None)
        # Reset class variable for test
        cls.total_users = 0
        u1 = cls("alice")
        u2 = cls("bob")
        u3 = cls("carol")
        _dynamic_test(self, cls.total_users == 3, "total_users increments with each instance", f"Expected total_users to be 3, got {cls.total_users}")

    def test_username_stored(self):
        import user_code
        importlib.reload(user_code)
        cls = getattr(user_code, 'User', None)
        # Reset class variable for test
        cls.total_users = 0
        u = cls("dave")
        username = getattr(u, 'username', None)
        _dynamic_test(self, username == "dave", "username instance variable is set correctly", f"Expected username 'dave', got {username}")

    def test_get_info_returns_tuple(self):
        import user_code
        importlib.reload(user_code)
        cls = getattr(user_code, 'User', None)
        # Reset class variable for test
        cls.total_users = 0
        u1 = cls("eve")
        u2 = cls("frank")
        res1 = u1.get_info() if u1 is not None else None
        res2 = u2.get_info() if u2 is not None else None
        _dynamic_test(self, isinstance(res1, tuple) and res1[0] == "eve" and res1[1] == 2, "get_info returns correct tuple for u1", f"Expected ('eve', 2), got {res1}")
        _dynamic_test(self, isinstance(res2, tuple) and res2[0] == "frank" and res2[1] == 2, "get_info returns correct tuple for u2", f"Expected ('frank', 2), got {res2}")

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

Lär dig att bygga rena, säkra och skalbara applikationer med objektorienterad programmering i Python. Täck grunderna i klasser och objekt, och gå sedan vidare till avancerade koncept såsom arv, komposition, polymorfism och inkapsling. Med tydliga förklaringar och praktiska exempel utvecklar du förmågan att designa Python-program som är kraftfulla, underhållbara och redo för verklig användning.

Lär dig de grundläggande byggstenarna i objektorienterad programmering i Python. Detta avsnitt behandlar klasser, objekt, metoder och variabler, vilket ger en stabil grund för att förstå hur OOP organiserar och strukturerar kod.

Challenge: Working with Instance and Class Variables

Lösning

Challenge: Working with Instance and Class Variables

Lösning