You will create a **robust division function** in Python that demonstrates comprehensive error handling. The goal is to ensure your function can safely divide two numbers, handle common errors gracefully, and provide clear feedback when something goes wrong.




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

class TestTask(unittest.TestCase):
    def test_valid_division(self):
        import user_code
        importlib.reload(user_code)
        result = getattr(user_code, 'robust_divide', None)
        output = result(10, 2) if result else None
        _dynamic_test(
            self,
            output == 5,
            "robust_divide returns correct result for (10, 2)",
            f"Expected 5, got {output} for (10, 2)",
        )

    def test_division_by_zero(self):
        import user_code
        importlib.reload(user_code)
        result = getattr(user_code, 'robust_divide', None)
        output = result(5, 0) if result else None
        _dynamic_test(
            self,
            output == "Cannot divide by zero",
            "robust_divide returns correct message for division by zero",
            f"Expected 'Cannot divide by zero', got {output}",
        )

    def test_invalid_type_first_arg(self):
        import user_code
        importlib.reload(user_code)
        result = getattr(user_code, 'robust_divide', None)
        output = result('10', 2) if result else None
        _dynamic_test(
            self,
            output == "Invalid input type",
            "robust_divide returns correct message for invalid first argument type",
            f"Expected 'Invalid input type', got {output}",
        )

    def test_invalid_type_second_arg(self):
        import user_code
        importlib.reload(user_code)
        result = getattr(user_code, 'robust_divide', None)
        output = result(8, '0') if result else None
        _dynamic_test(
            self,
            output == "Invalid input type",
            "robust_divide returns correct message for invalid second argument type",
            f"Expected 'Invalid input type', got {output}",
        )

    def test_float_division(self):
        import user_code
        importlib.reload(user_code)
        result = getattr(user_code, 'robust_divide', None)
        output = result(7.5, 2.5) if result else None
        _dynamic_test(
            self,
            output == 3.0,
            "robust_divide returns correct result for (7.5, 2.5)",
            f"Expected 3.0, got {output} for (7.5, 2.5)",
        )

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

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Challenge: Robust Division Function

Lösning