RugvAI Labs

Mini-Project: Number Guessing Game

You'll build a number guessing game in 20 minutes -- the computer picks a secret number, and you keep guessing until you get it. By the end, you'll have used loops, conditionals, and randomness together for the first time.

#What you'll build

A guessing game where the computer secretly picks a number between 1 and 100 and your job is to find it. After each guess, the program tells you whether you went too high or too low. When you finally land on the right number, it tells you how many tries it took.

Sample interaction

text

I picked a number between 1 and 100. Can you guess it?
Your guess: 50
Too high! Try again.
Your guess: 25
Too low! Try again.
Your guess: 37
Too high! Try again.
Your guess: 31
You got it in 4 tries!

#What you'll learn

How to generate a random integer with random.randint
How to keep asking for input with a while loop
How to compare values and give different feedback with if/elif/else

#Step 1: Pick a secret number

The random module ships with Python -- no install needed. random.randint(1, 100) returns a random integer between 1 and 100, inclusive.

pythonrunnable cell

import random

secret = random.randint(1, 100)
print(f"(Debug: the secret is {secret})")

Print the secret for now so you can verify the rest of the logic. We'll remove that line at the end.

What Do You Think?

How is random.randint(1, 6) different from range(1, 6)?

The answer is randint can return 6; range stops at 5. This is one of Python's most confusing inconsistencies — range(a, b) excludes b (so range(1, 6) gives 1, 2, 3, 4, 5), but random.randint(a, b) INCLUDES both ends (so it can return 1, 2, 3, 4, 5, OR 6). If you want a random index for a list of length 6, use random.randint(0, 5) or — better — random.randrange(6), which matches range's exclusive-end behavior.

Quick check

What's the range of `random.randint(1, 100)`?

#Step 2: Ask for a guess

Read input from the user and convert it to an integer. Remember -- input() always returns a string, so you have to call int() if you want to compare it to a number.

pythonrunnable cell

Input for this program

This code calls input(). Python here can't pause to ask you, so type the answers below before running — one value per line, in the order the program asks for them.

guess = int(input("Your guess: "))
print(f"You guessed {guess}")

If the user types something that isn't a number, int() will crash with a ValueError. We'll ignore that for now and add validation in a later lesson on error handling.

What Do You Think?

What happens at runtime? secret = 42 guess = input("Guess: ") # user types 42 print(guess == secret)

The answer is False. The user typed 42, but input() always gives back a STRING — so guess is "42" (the string), not 42 (the integer). When Python compares "42" == 42, it returns False because a string and an int are never equal, even when they look identical. No crash — just a silently wrong answer. The fix: guess = int(input("Guess: ")). This is why every number-from-input pattern has that int() call.

#Step 3: Compare guess to secret

Three cases -- guess is too high, too low, or correct. That maps perfectly to if/elif/else.

pythonreference · read-only

if guess < secret:
    print("Too low! Try again.")
elif guess > secret:
    print("Too high! Try again.")
else:
    print("You got it!")

Run this once with guess = secret to make sure the "got it" branch works, then with a wrong guess to make sure the high/low branches work.

Quick check

Why use `elif` instead of two separate `if` statements?

#Step 4: Loop until correct

A while True loop runs forever -- unless you break out of it. Combine that with the comparison from Step 3 so the program keeps asking until the user wins.

pythonreference · read-only

while True:
    guess = int(input("Your guess: "))
    if guess < secret:
        print("Too low! Try again.")
    elif guess > secret:
        print("Too high! Try again.")
    else:
        print("You got it!")
        break

break immediately exits the closest loop. Without it, your game would run forever even after the user won.

What Do You Think?

What does this print? for i in range(5): if i == 2: break print(i) print("done")

The answer is 0 1 done. The loop prints 0, then 1. When i reaches 2, the if condition matches and break fires BEFORE the print — so 2 is never printed. The loop ends entirely, and execution jumps to the line after the loop, printing "done". Compare with continue, which would skip just the print for i == 2 and keep looping (output: 0 1 3 4 done). Break = leave the room. Continue = skip this turn.

#Step 5: Count the tries

Track how many guesses the user took with a counter. Increment it on every guess. Display it when they win.

pythonrunnable cell

Input for this program

This code calls input(). Python here can't pause to ask you, so type the answers below before running — one value per line, in the order the program asks for them.

import random

secret = random.randint(1, 100)
tries = 0

print("I picked a number between 1 and 100. Can you guess it?")

while True:
    guess = int(input("Your guess: "))
    tries += 1
    if guess < secret:
        print("Too low! Try again.")
    elif guess > secret:
        print("Too high! Try again.")
    else:
        print(f"You got it in {tries} tries!")
        break

That's the full game. Optimal play with binary search wins in 7 tries or fewer for any number between 1 and 100 -- see if you can spot why.

#Now build it yourself

Mini project

Number Guessing Game with try counter

~20 min

Build a game where the computer picks a number from 1 to 100. The user keeps guessing -- you tell them higher/lower after each guess. When they win, print how many tries it took. Bonus: rate them ('Lucky!' for under 7, 'Solid!' for 7-10, 'Keep trying!' for 11+).

Expected output

I picked a number between 1 and 100. Can you guess it?
Your guess: 50
Too high! Try again.
Your guess: 25
Too low! Try again.
Your guess: 37
Too high! Try again.
Your guess: 31
You got it in 4 tries! Lucky!

Your code

pythonrunnable cell

import random

# TODO: pick a secret number between 1 and 100
# TODO: initialise the try counter

print("I picked a number between 1 and 100. Can you guess it?")

# TODO: while-True loop that asks for a guess
#   - increment counter
#   - if too low: print 'Too low!'
#   - if too high: print 'Too high!'
#   - if correct: print 'You got it in N tries!' and break
# TODO: after the loop, print rating based on tries

#Now make it your own

Try one of these variations:

Reverse it -- YOU pick the secret, the computer guesses. Use binary search: it should win every time in 7 tries or fewer.
Hard mode -- limit the player to 7 guesses. If they run out, print "Game over -- the number was X".
Hot/cold hints -- after each guess, also say "getting warmer" or "getting colder" based on whether they're closer or further than last time.

#What's next

You just wrote your first program with a real game loop -- the kind that powers every CLI tool, every chat bot, and every simulator. Next up: FizzBuzz, the most famous interview problem in software history. Five minutes of code that combines everything you've learned so far -- loops, conditionals, and the modulo operator -- into a single tiny program.