When working with legal regulations, it is common to compare different versions to identify what has changed. In this challenge, you will use two hardcoded lists in Python—each representing a set of regulation section numbers or names from two versions of a regulation. Your task is to compare these lists and clearly display which sections have been added and which have been removed. To do this effectively, you will need to find the differences between the lists, then format your output so that it is easy to see which sections are new and which are no longer present. This approach helps legal professionals quickly understand regulatory changes and focus their compliance efforts.


import unittest
import user_code
import ast
import re   
import importlib
import csv
import unittest
import importlib
import io
from contextlib import redirect_stdout

class TestTask(unittest.TestCase):
    def test_added_and_removed(self):
        import user_code
        importlib.reload(user_code)
        f = io.StringIO()
        old = ["Section 1", "Section 2", "Section 3", "Section 4"]
        new = ["Section 2", "Section 3", "Section 4", "Section 5", "Section 6"]
        with redirect_stdout(f):
            user_code.compare_regulations(old, new)
        out = normalize_text(f.getvalue())
        _dynamic_test(
            self,
            "added sections: section 5, section 6" in out,
            "Correctly prints added sections for test case 1",
            f"Output for added sections incorrect: {out}"
        )
        _dynamic_test(
            self,
            "removed sections: section 1" in out,
            "Correctly prints removed sections for test case 1",
            f"Output for removed sections incorrect: {out}"
        )

    def test_no_changes(self):
        import user_code
        importlib.reload(user_code)
        f = io.StringIO()
        old = ["Section A", "Section B"]
        new = ["Section A", "Section B"]
        with redirect_stdout(f):
            user_code.compare_regulations(old, new)
        out = normalize_text(f.getvalue())
        _dynamic_test(
            self,
            "added sections:" in out and "removed sections:" in out and "added sections:" in out and not any(s in out for s in ["section c", "section d"]),
            "Prints labels with no added/removed sections",
            f"Output for no changes incorrect: {out}"
        )

    def test_all_removed(self):
        import user_code
        importlib.reload(user_code)
        f = io.StringIO()
        old = ["Section 1", "Section 2"]
        new = []
        with redirect_stdout(f):
            user_code.compare_regulations(old, new)
        out = normalize_text(f.getvalue())
        _dynamic_test(
            self,
            "added sections:" in out and "removed sections: section 1, section 2" in out,
            "Prints all old sections as removed when new list is empty",
            f"Output for all removed incorrect: {out}"
        )

    def test_all_added(self):
        import user_code
        importlib.reload(user_code)
        f = io.StringIO()
        old = []
        new = ["Section X", "Section Y"]
        with redirect_stdout(f):
            user_code.compare_regulations(old, new)
        out = normalize_text(f.getvalue())
        _dynamic_test(
            self,
            "added sections: section x, section y" in out and "removed sections:" in out,
            "Prints all new sections as added when old list is empty",
            f"Output for all added incorrect: {out}"
        )

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: Regulation Comparator

Solution

Challenge: Regulation Comparator

Solution