
import unittest
import user_code
import ast
import re   
import importlib
import csv
import unittest
import importlib
import sys
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt

class TestTask(unittest.TestCase):
    def setUp(self):
        # Patch plt.show to avoid displaying plots during tests
        self._show_backup = plt.show
        plt.show = lambda *args, **kwargs: None

    def tearDown(self):
        plt.show = self._show_backup

    def get_line_data(self, ax):
        # Get all lines from the axes
        lines = ax.get_lines()
        if not lines:
            return [], []
        xdata = lines[0].get_xdata()
        ydata = lines[0].get_ydata()
        return list(xdata), list(ydata)

    def test_connects_vertices_in_order(self):
        import user_code
        importlib.reload(user_code)
        plt.clf()
        vertices = [(0, 0), (2, 0), (1, 2)]
        user_code.plot_polygon(vertices)
        ax = plt.gca()
        xdata, ydata = self.get_line_data(ax)
        expected_x = [0, 2, 1, 0]
        expected_y = [0, 0, 2, 0]
        _dynamic_test(
            self,
            xdata == expected_x and ydata == expected_y,
            "Vertices are connected in the correct order and polygon is closed",
            f"Expected x: {expected_x}, y: {expected_y}; got x: {xdata}, y: {ydata}"
        )

    def test_polygon_closed(self):
        import user_code
        importlib.reload(user_code)
        plt.clf()
        vertices = [(1, 1), (4, 1), (4, 4), (1, 4)]
        user_code.plot_polygon(vertices)
        ax = plt.gca()
        xdata, ydata = self.get_line_data(ax)
        # Check if the last point connects to the first
        _dynamic_test(
            self,
            xdata[0] == xdata[-1] and ydata[0] == ydata[-1],
            "Polygon is closed by connecting last vertex to the first",
            f"Polygon is not closed: start ({xdata[0]}, {ydata[0]}), end ({xdata[-1]}, {ydata[-1]})"
        )

    def test_vertices_as_points(self):
        import user_code
        importlib.reload(user_code)
        plt.clf()
        vertices = [(3, 1), (6, 1), (6, 3), (3, 3)]
        user_code.plot_polygon(vertices)
        ax = plt.gca()
        lines = ax.get_lines()
        _dynamic_test(
            self,
            len(lines) > 0,
            "Plot contains at least one line object",
            "No line object found in plot"
        )
        xdata = lines[0].get_xdata()
        ydata = lines[0].get_ydata()
        # Check that all original vertices are present as points in the plot
        points = set((x, y) for x, y in zip(xdata, ydata))
        for vx, vy in vertices:
            _dynamic_test(
                self,
                (vx, vy) in points,
                f"Vertex ({vx}, {vy}) is plotted as a point",
                f"Vertex ({vx}, {vy}) is missing from the plot"
            )

    def test_handles_three_or_more_vertices(self):
        import user_code
        importlib.reload(user_code)
        plt.clf()
        # Triangle
        vertices3 = [(0, 0), (1, 0), (0.5, 1)]
        user_code.plot_polygon(vertices3)
        ax = plt.gca()
        xdata, ydata = self.get_line_data(ax)
        _dynamic_test(
            self,
            len(xdata) == 4 and len(ydata) == 4,
            "Function handles polygons with three vertices (triangle)",
            f"Triangle not plotted correctly: x={xdata}, y={ydata}"
        )
        plt.clf()
        # Pentagon
        vertices5 = [(0, 0), (1, 0), (1.5, 1), (0.5, 2), (-0.5, 1)]
        user_code.plot_polygon(vertices5)
        ax = plt.gca()
        xdata, ydata = self.get_line_data(ax)
        _dynamic_test(
            self,
            len(xdata) == 6 and len(ydata) == 6,
            "Function handles polygons with five vertices (pentagon)",
            f"Pentagon not plotted correctly: x={xdata}, y={ydata}"
        )

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

Learn the fundamentals of geometric modelling using Python. Explore how to represent, manipulate, and approximate geometric figures programmatically. This course covers basic shapes, transformations, and practical approximation techniques, making geometric concepts accessible and interactive.

Get started with the core concepts of geometric modelling and how Python can be used to represent and manipulate basic shapes.

Delve into geometric transformations such as translation, rotation, and scaling, and see how they affect shapes in Python.

Learn how to approximate curves and complex shapes using polygons and other techniques in Python.

Challenge: Polygon Plotting

Solution