import unittest
import io
import sys


def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)


class TestUserCode(unittest.TestCase):

    def test_beautifulsoup_imported(self):
        with open("user_code.py", "r") as f:
            src = f.read()

        condition = "from bs4 import BeautifulSoup" in src

        _dynamic_test(
            self,
            condition,
            "The `BeautifulSoup` class is imported.",
            "Expected import: `from bs4 import BeautifulSoup`."
        )

    def test_soup_declared(self):
        import user_code
        condition = hasattr(user_code, "soup")

        _dynamic_test(
            self,
            condition,
            "The `soup` variable is declared.",
            "`soup` variable is missing."
        )

    def test_soup_is_beautifulsoup(self):
        import user_code
        from bs4 import BeautifulSoup

        try:
            s = user_code.soup
            condition = isinstance(s, BeautifulSoup)
            fail_msg = "`soup` must be a BeautifulSoup object."
        except Exception:
            condition = False
            fail_msg = "`soup` is missing or invalid."

        _dynamic_test(
            self,
            condition,
            "`soup` is a valid BeautifulSoup instance.",
            fail_msg
        )

    def test_html_is_string(self):
        import user_code

        try:
            html_val = user_code.html
            condition = isinstance(html_val, str)
            fail_msg = f"`html` must be a string but is `{type(html_val).__name__}`."
        except:
            condition = False
            fail_msg = "`html` variable missing."

        _dynamic_test(
            self,
            condition,
            "`html` contains decoded HTML.",
            fail_msg
        )

    def test_ul_children_printed(self):
        import user_code
        import importlib

        # Capture stdout
        captured = io.StringIO()
        sys.stdout = captured

        importlib.reload(user_code)

        sys.stdout = sys.__stdout__

        # real printed output
        printed = captured.getvalue().splitlines()
        printed_clean = [line for line in printed if line.strip()]

        # expected from BeautifulSoup
        expected_clean = []
        for child in user_code.soup.ul.children:
            text = str(child).strip()
            if text:
                expected_clean.append(str(child))

        # Length check
        if len(printed_clean) != len(expected_clean):
            _dynamic_test(
                self,
                False,
                "",
                f"Expected {len(expected_clean)} printed UL elements, got {len(printed_clean)}."
            )
            return

        # Compare each printed line
        for p, e in zip(printed_clean, expected_clean):
            if p.strip() != e.strip():
                _dynamic_test(
                    self,
                    False,
                    "",
                    f"Expected `{e}`, but got `{p}`."
                )
                return

        _dynamic_test(
            self,
            True,
            "All `ul` children were printed correctly.",
            ""
        )


if __name__ == "__main__":
    unittest.main()


test_code.py

Learn to extract valuable data from websites automatically. Master techniques to gather information efficiently, enabling you to perform in-depth analysis, make data-driven decisions, and unlock new insights from the vast ocean of online information.

Explore the structure of an HTML file, learn how to load it efficiently, and gain practical skills in working with the data it contains.

Explore the basics of Beautiful Soup to extract data from HTML documents. Learn how to navigate the structure of HTML, access specific elements, and work with their child elements to build a strong foundation in web scraping.

Master working with element attributes and content using Beautiful Soup. Gain the skills to extract specific information, search elements by attribute values, and use advanced techniques to efficiently parse and analyze HTML data.

Challenge: Iterating Over Lists

解答