Summary  
Local vs. global variables define the scope and lifetime of data in code, where global variables are accessible throughout the entire program and local variables exist only within the function or block in which they are declared.

General domain of usage  
Software development (managing variable scope in code modules)


import unittest
import user_code
import ast
import re   
import importlib
import csv
import unittest
import importlib
import sys
import io

class TestTask(unittest.TestCase):
    def test_global_x_modified(self):
        import user_code
        importlib.reload(user_code)
        x_value = getattr(user_code, 'x', None)
        _dynamic_test(
            self,
            x_value == 20,
            "Global variable x was correctly changed to 20.",
            f"Expected global x to be 20, got {x_value}",
        )

    def test_local_y_not_global(self):
        import user_code
        importlib.reload(user_code)
        has_y = hasattr(user_code, 'y')
        _dynamic_test(
            self,
            not has_y,
            "Local variable y is not accessible outside the function.",
            "Variable y should not be defined globally.",
        )

    def test_return_string_content(self):
        import user_code
        importlib.reload(user_code)
        output = getattr(user_code, 'output', None)
        expected = "x is 20, y is 5"
        _dynamic_test(
            self,
            isinstance(output, str) and output.strip() == expected,
            f"Returned string is correct: '{expected}'",
            f"Expected return string '{expected}', got '{output}'",
        )

    def test_x_printed_value(self):
        import user_code
        importlib.reload(user_code)
        f = io.StringIO()
        sys_stdout = sys.stdout
        sys.stdout = f
        importlib.reload(user_code)
        sys.stdout = sys_stdout
        output = normalize_text(f.getvalue())
        _dynamic_test(
            self,
            "20" in output,
            "Printed output includes updated value of x.",
            f"Expected to see '20' printed in output, got: {output}",
        )

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.

Lokale vs. Globale Variabler

Løsning