Guess My Number

The computer picks a secret number from 1 to 100, and you hunt it down armed with nothing but “Higher!” and “Lower!“. One while loop, one conditional chain, and the random module doing the picking.

The program

import random
 
secret = random.randint(1, 100)
guesses = 0
guess = 0
 
print("I am thinking of a number from 1 to 100.")
 
while guess != secret:
    guess = int(input("Your guess: "))
    guesses = guesses + 1
    if guess < secret:
        print("Higher!")
    elif guess > secret:
        print("Lower!")
    else:
        print("Got it in", guesses, "guesses!")

Read it before you run it

Predict in writing first — then run the program and grade yourself.

• guess starts at 0. Why is that guaranteed to be wrong, and what does the while loop’s condition do with that fact?
• Which branch runs on the winning guess — and why does the loop stop immediately afterwards?
• You guess 50 and see Higher!. Exactly which numbers are still possible? A strategy is hiding in that answer — the same one that wins Twenty Questions.

Make it yours

1. One line. Make the secret range 1 to 1000 — then keep the welcome message honest.
2. A few lines. Add Way higher! and Way lower! responses when a guess misses by more than 25.
3. A real change. Allow only seven guesses, and announce a win or a loss when the game ends. Seven is enough for 1 to 100 — your answer to the third prediction above explains why.

Curriculum connection

C1.4

determine the appropriate expressions and instructions to use in a programming statement, taking into account the order of operations

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C2.4

write programs that include sequential, selection, and repeating events

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C3.1

analyze existing code to understand the components and outcomes of the code

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C3.4

write programs that make use of external or add-on modules or libraries

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