Lab 2b — Conditions

Preparation

5 minutes

Download the zip file for this lab, located above. This zip file has worlds that you will use for Bit. Extract the files and put them in your cs110 directory in a folder called lab2b.

Exercise 1

10 minutes

Bit’s job is to paint a green box. There are two worlds. The first world starts like this:

After Bit paints a green box, it looks like this:

The second world looks like this:

After Bit paints a green box, it looks like this:

You have starter code in paint-the-box.py.

Notes:

• Your code needs to be general enough to solve both worlds.
• Notice that Bit ends where it starts, facing the same direction.
• Think about the stopping condition — when does Bit stop painting?
• This problem does not use and or or.

Discuss with the TA:

• What was your stopping condition?
• What other conditions did you need?

Red Roses

15 minutes

In this problem, Bit needs to turn all of the roses red. Here is one of the worlds:

At the end, Bit should have turned all of the blue and green squares into red ones:

You have starter code in red-roses.py.

Notes:

• What is the stopping condition?
• What other conditions do you need?

Discuss with the TA:

• Compare your solution on this problem to the solution on the previous problem.

Clear green

15 minutes

In this problem, Bit needs to clear only the green squares that are next to the black squares. One of the worlds looks like this:

At the end, Bit should have cleared all of the green squares that are next to a black square:

Notes:

• What is the stopping condition?
• What conditions can Bit use to decide whether to erase a square?

Remember, use bit.erase() to erase a square.

Discuss with the TA:

• Did you use two ifs or one if and one elif?
• Is there any difference?

Wrapup

5 minutes

Discuss any questions about conditions in while loops and if statements.

Grading

To finish this lab and receive a grade, take the canvas quiz.