09. The print toolkit — Homework solutions

The .py solution files are in exercises/09/homework/solutions/.

Problem 1 — A stat row

Problem. Print three values on one line, comma-separated.

Worked solution.

print("Keiko", 7, 95)

Output (spaces between the values):

Keiko 7 95

Common mistakes.

  • Quoting the numbers. 7 and "7" look alike but are different types; the problem wants numbers.

Problem 2 — A polished line

Problem. Build one exact sentence with an f-string.

How to think about it. Put the variables in {} placeholders at the right positions, with the surrounding text (spaces, words) as literal characters in the string.

Worked solution.

name = "Keiko"
hp = 95
level = 7

print(f"{name} has {hp} HP at level {level}")

Output:

Keiko has 95 HP at level 7

Common mistakes.

  • Forgetting spaces around the words inside the f-string, giving Keikohas95HPatlevel7. The spaces outside the {} braces are part of the string — put them exactly where you want them.

Problem 3 — Spaced out

Problem. Three lines, a blank line between each, five print calls.

Worked solution.

print("Line one")
print()
print("Line two")
print()
print("Line three")

Common mistakes.

  • Writing print(" ") (a space) instead of print() (nothing). Both look blank, but print() says "empty line" plainly.

Challenge — Receipt

Problem. Print a small receipt: item lines, a blank line, then a total.

Worked solution.

apple = 3
bread = 2
milk = 4
total = apple + bread + milk

print(f"apple: {apple}")
print(f"bread: {bread}")
print(f"milk: {milk}")
print()
print(f"Total: {total}")

Output:

apple: 3
bread: 2
milk: 4

Total: 9

Common mistakes.

  • Typing the total as a literal 9 instead of computing it. A computed total updates when a price changes; a typed one won't.

Done?

You can now show values exactly how you want. The last chapter of this part — Reading error messages — covers the red text Python prints when something breaks.