
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

Bemästra packning/uppackning, flexibla funktionsargument, högre ordningens funktioner, lambdas, variabelräckvidd, closures, iteratorer och dekoratörer. Utformad för studenter som har genomfört en introduktionskurs i Python och vill skriva mer effektiv, uttrycksfull och kraftfull kod.

Utforska konsten att packa och packa upp listor, tupler och ordböcker för att skriva mer uttrycksfull och effektiv Python-kod.

Fördjupa dig i världen av högre ordningens funktioner, att skicka funktioner som argument och att skriva koncisa anonyma funktioner med lambda.

Avslöja mysterierna kring variabelns räckvidd och lär dig hur nästlade funktioner och closures möjliggör kraftfull inkapsling.

Fördjupa dig i Pythons iterationsprotokoll, anpassade iteratorer och generatorfunktioner för effektiv databehandling.

Utmaning: Lambda med filter

Lösning