Abstraction

Have a look at these figures:

On a high level, we could say they are similar because both of them are light bulbs, and they are different because one is turned on while the other is turned off.

Let's create a function that can produce either kind of light bulb. The function has a parameter to express the difference:

def light_bulb(on: bool) -> Graphic:

Let's add another parameter to make it possible to produce light bulbs of any desired size.

def light_bulb(size: float, on: bool) -> Graphic:

Decomposition

Let's decompose a light bulb into the following three components:

The bulb, the wire, and the cap. Note that the two loops of the wire are a bit awkward: because we cannot cut holes into graphics, we "simulated" a hole by overlaying a graphic in the background color.

Colors

Before implementing code to compose light bulbs, let's look at the different colors used.

Available Components

Now let's compose a light bulb from a bulb, a wire, and a cap, and let's compose those from more basic components. Assume that, besides the basic PyTamaro functions such as rectangle, you also already have functions to produce the following kinds of shapes.

Circles

Import the circle function from your toolbox. If you haven't collected that function yet, implement it here or follow the Circles activity.

Rounded Edges

Import the rounded_edge function from your toolbox. If you haven't collected that function yet, implement it here or follow the Rounded Edge activity.

Isosceles Trapezoids

Import the isosceles_trapezoid function from your toolbox. If you haven't collected that function yet, implement it here or follow the Isosceles Trapezoid activity.

Corner Loops

Import the corner_loop function from your toolbox. If you haven't collected that function yet, implement it here or follow the Looped Square activity.

Composition

Now let's use the available components to implement the three top-level components: the bulb, the wire, and the cap.

Bulb

Create an isosceles trapezoid with a top length equal to the diameter, a bottom length equal to 0.4 times the diameter, and a height of 0.7 times the diameter.

Wire

Use the corner_loop function from above. The width of the entire wire should be divided into 10 parts: 4 wire parts of the given line_width, interleaved by 3 gap parts of twice the given line_width.

Cap

A cap should have five windings. A winding is as wide as the diameter of the cap. The thickness (height) of one complete winding (bright and dark parts together) is twice the line_width of the cap.

Putting It All Together

Make sure to use the appropriate colors for the glass and wire, depending on whether the bulb is on or off.

What You Learned

You practiced decomposition by breaking down the problem into multiple functions, and you practiced abstraction, because the functions have parameters and thus a function can produce an entire family of similar graphics.