Update resources for completion

Added additional code files, e.g. `shape.py` so that readers can
draw the turtle shape. Also renamed files to match the tutorial, and
updated the README file.

Author: martin-martin

python-sequences/README.md

@@ -1 +1,5 @@
-Final version of `shaped_abc.py`, which contains the `ShapesPoints` class definition.
+# Python Sequences: A Comprehensive Guide
+
+This folder contains source code for the Real Python tutorial [Python Sequences: A Comprehensive Guide](https://realpython.com/python-sequences-comprehensive-guide/).
+
+For more code, intermediate steps, and additional explanation, check out the associated tutorial.

python-sequences/draw_shape.py

@@ -0,0 +1,16 @@
+import turtle
+
+from shape import ShapePoints
+
+triangle = ShapePoints([(100, 100), (-200, 100), (-200, -200)])
+
+# Draw the shape using turtle graphics
+turtle.penup()
+# Move to the first point
+turtle.setposition(triangle[0])
+turtle.pendown()
+# Draw lines to the other points
+for point in triangle[1:]:
+    turtle.setposition(point)
+
+turtle.done()

python-sequences/shape.py

@@ -0,0 +1,27 @@
+class ShapePoints:
+    """
+    A ShapePoints object represents a collection of points
+
+    Attributes:
+    - points: sequence of points, where each point is a
+        tuple (x, y)
+    """
+
+    def __init__(self, points):
+        self.points = list(points)
+        if points and self.points[0] != self.points[-1]:
+            self.points.append(self.points[0])
+
+    def __repr__(self):
+        return f"ShapePoints({self.points})"
+
+    def __getitem__(self, index):
+        return self.points[index]
+
+    def __len__(self):
+        if self.points:
+            return len(self.points) - 1
+        return 0
+
+    def __iter__(self):
+        return iter(self.points)