Introducing Python, 2nd Edition

Chapter 1. A Taste of Py

Only ugly languages become popular. Python is the one exception.

Don Knuth

Mysteries

Let’s begin with two mini-mysteries and their solutions. What do you think the following two lines mean?

(Row 1): (RS) K18,ssk,k1,turn work.
(Row 2): (WS) Sl 1 pwise,p5,p2tog,p1,turn.

It looks technical, like some kind of computer program. Actually, it’s a knitting pattern; specifically, a fragment describing how to turn the heel of a sock, like the one in Figure 1-1.

Figure 1-1. Knitted socks

This makes as much sense to me as a Sudoku puzzle does to one of my cats, but my wife understands it perfectly. If you’re a knitter, you do, too.

Let’s try another mysterious text, found on an index card. You’ll figure out its purpose right away, although you might not know its final product:

  1/2 c. butter or margarine
  1/2 c. cream
  2 1/2 c. flour
  1 t. salt
  1 T. sugar
  4 c. riced potatoes (cold)

Be sure all ingredients are cold before adding flour.
Mix all ingredients.
Knead thoroughly.
Form into 20 balls.  Store cold until the next step.
For each ball:
  Spread flour on cloth.
  Roll ball into a circle with a grooved rolling pin.
  Fry on griddle until brown spots appear.
  Turn over and fry other side.

Even if you don’t cook, you probably recognized that it’s a recipe¹: a list of food ingredients followed by directions for preparation. But what does it make? It’s lefse, a Norwegian delicacy ...