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

class TestTask(unittest.TestCase):
    def test_only_long_strings_returned(self):
        import user_code
        importlib.reload(user_code)
        data = ["cat", "house", "sun", "elephant"]
        expected = ["house", "elephant"]
        result = user_code.filter_long_strings(data)
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Returns only strings longer than 3 characters.",
            f"Expected {expected}, got {result}",
        )

    def test_returns_empty_list_when_none_long(self):
        import user_code
        importlib.reload(user_code)
        data = ["a", "be", "see"]
        expected = []
        result = user_code.filter_long_strings(data)
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Returns empty list when no strings are longer than 3 characters.",
            f"Expected {expected}, got {result}",
        )

    def test_mixed_lengths_preserves_order(self):
        import user_code
        importlib.reload(user_code)
        data = ["dog", "tree", "sky", "river"]
        expected = ["tree", "river"]
        result = user_code.filter_long_strings(data)
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Handles mix of short and long strings, preserves order.",
            f"Expected {expected}, got {result}",
        )

    def test_all_long_strings(self):
        import user_code
        importlib.reload(user_code)
        data = ["house", "river", "apple"]
        expected = ["house", "river", "apple"]
        result = user_code.filter_long_strings(data)
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Returns all strings if all are longer than 3 characters.",
            f"Expected {expected}, got {result}",
        )

    def test_empty_input(self):
        import user_code
        importlib.reload(user_code)
        data = []
        expected = []
        result = user_code.filter_long_strings(data)
        _dynamic_test(
            self,
            isinstance(result, list) and result == expected,
            "Returns empty list for empty input.",
            f"Expected {expected}, got {result}",
        )

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

Bliv fortrolig med pakning/udpaking, fleksible funktionsargumenter, højere-ordens funktioner, lambdaer, variabelscope, closures, iteratorer og dekoratører. Udviklet til kursister, der har gennemført et introduktionskursus i Python og ønsker at skrive mere effektiv, udtryksfuld og kraftfuld kode.

Udforsk kunsten at pakke og udpakke lister, tupler og ordbøger for at skrive mere udtryksfuld og effektiv Python-kode.

Dyk ned i verdenen af højereordensfunktioner, overførsel af funktioner som argumenter og skrivning af korte anonyme funktioner med lambda.

Opdag hemmelighederne bag variabelscope, og lær hvordan indlejrede funktioner og closures muliggør effektiv indkapsling.

Dyk ned i Pythons iterationsprotokol, brugerdefinerede iteratorer og generatorfunktioner for effektiv databehandling.

Udfordring: Lambda med filter

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