Values, Types, Variable Names, and Keywords

Read these examples of using the 'print' and 'type' functions. You can also try to use them in the Repl.it command line.

Exercise 1

Repeating my advice from the previous chapter, whenever you learn a new feature, you should try it out in interactive mode and make errors on purpose to see what goes wrong.

  1. We've seen that n = 42 is legal. What about 42 = n?
  2. How about x = y = 1?
  3. In some languages every statement ends with a semi-colon, ;. What happens if you put a semi-colon at the end of a Python statement?
  4. What if you put a period at the end of a statement?
  5. In math notation, you can multiply x and y like this: x y. What happens if you try that in Python?


Exercise 2

Practice using the Python interpreter as a calculator:

  1. The volume of a sphere with radius r is 4/3 π r3. What is the volume of a sphere with radius 5?
  2. Suppose the cover price of a book is $24.95, but bookstores get a 40% discount. Shipping costs $3 for the first copy and 75 cents for each additional copy. What is the total wholesale cost for 60 copies?
  3. If I leave my house at 6:52 am and run 1 mile at an easy pace (8:15 per mile), then 3 miles at tempo (7:12 per mile) and 1 mile at easy pace again, what time do I get home for breakfast?