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

class TestTask(unittest.TestCase):
    # def test_countdown_output(self):
    #     import user_code
    #     importlib.reload(user_code)
    #     f = io.StringIO()
    #     sys_stdout = sys.stdout
    #     sys.stdout = f
    #     try:
    #         user_code.print_countdown()
    #     finally:
    #         sys.stdout = sys_stdout
    #     output = f.getvalue()
    #     # Split output by lines and strip whitespace
    #     lines = [line.strip() for line in output.strip().splitlines() if line.strip()]
    #     expected = [str(i) for i in range(5, 0, -1)]
    #     _dynamic_test(
    #         self,
    #         lines == expected,
    #         "Countdown prints numbers 5 to 1 in order",
    #         f"Expected output: {expected}, got: {lines}",
    #     )

    def test_countdown_timing(self):
        import user_code
        importlib.reload(user_code)
        start = time.time()
        # Suppress output
        sys_stdout = sys.stdout
        sys.stdout = io.StringIO()
        try:
            user_code.print_countdown()
        finally:
            sys.stdout = sys_stdout
        end = time.time()
        elapsed = end - start
        # Should be at least 4.5 seconds and less than 7 seconds (accounting for slight timing drift)
        _dynamic_test(
            self,
            4.5 <= elapsed <= 7,
            "Countdown waits about one second between prints (total time correct)",
            f"Countdown timing incorrect: elapsed {elapsed:.2f} seconds",
        )

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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Explore practical automation scenarios using Python, from simple repetitive tasks to essential system operations. Alternate between conceptual learning and hands-on practice.

Challenge: Print Countdown

解答