if/elif/else, the six comparators, and/or/not, booleans, importing modules, and the random module. Three challenges: a warm-up, an applied script, and a mini-project.
1. Even/Odd & Sign Checker (warm-up) — checks a number for even/odd and, separately, positive/negative/zero:
print(f"Welcome to Even/Odd & Sign Checker App")
# Convert input string to an integer
number = int(float(input("Enter a number: ")))
# Check if the remainder when divided by 2 is 0
if number % 2 == 0:
print(f"{number} is Even")
else:
print(f"{number} is Odd")
# Check the sign, independent of even/odd
if number == 0:
print(f"{number} is a Zero number")
elif number < 0:
print(f"{number} is a Negative Integer")
else:
print(f"{number} is a Positive Integer")
2. Number Guessing Game (applied) — generates a secret number with random.randint(), then tells the player if they were exact, close (within 3), or far off, plus which direction to guess next:
import random
def calculate_probability(min_val, max_val):
"""Calculates the percentage chance of guessing correctly in an inclusive range [min_val, max_val]."""
total_outcomes = (max_val - min_val) + 1
return (1 / total_outcomes) * 100
print("Welcome to my number Guessing Game!")
min_range = 1
max_range = 10
win_percentage = calculate_probability(min_range, max_range)
print(f"Your probability of guessing correctly is {win_percentage:.1f}%\n")
guess_num = int(input(f"Guess the number from {min_range} - {max_range}: "))
secret_num = random.randint(min_range, max_range)
difference = abs(guess_num - secret_num)
if guess_num == secret_num:
print(f"🎉 Exactly right! The secret number was {secret_num}.")
elif difference <= 3:
if guess_num < secret_num:
print(f"Close! You were within 3. Try guessing HIGHER next time. (Secret: {secret_num})")
else:
print(f"Close! You were within 3. Try guessing LOWER next time. (Secret: {secret_num})")
else:
if guess_num < secret_num:
print(f"Far off! Try guessing HIGHER next time. (Secret: {secret_num})")
else:
print(f"Far off! Try guessing LOWER next time. (Secret: {secret_num})")
3. Login Gatekeeper (mini-project) — checks a hardcoded username/password against user input with boolean logic, covering four outcomes, plus a random welcome message on success:
import random
print("Welcome to Login Gatekeeper")
welcome_msg = ("Welcome back!", "Heya there!", "Aloha amigo!")
secret_usr = "johnny123"
secret_pwd = "letmein2"
check_usr = input("Enter your username : \n")
check_pwd = input("Enter your password : \n")
if secret_usr.lower() == check_usr.lower() and secret_pwd.lower() == check_pwd.lower():
print("You are logged in")
print(f"{random.choice(welcome_msg)}")
elif secret_usr.lower() == check_usr.lower() and secret_pwd.lower() != check_pwd.lower():
print("Password is incorrect")
elif secret_usr.lower() != check_usr.lower() and secret_pwd.lower() == check_pwd.lower():
print("Username is incorrect")
else:
print("Wrong username or password !")
The login gatekeeper came together cleanly on the first pass — the four-outcome branching mapped naturally onto if/elif/elif/else. The other two needed a second look:
if/elif/else block after the even/odd check cut the code in half with identical output.and/or. The guessing game’s “close vs. far, higher vs. lower” logic works with nested if blocks, but the challenge was really asking for compound conditions like guess_num < secret_num and difference <= 3 chained directly. Both get the same result — nesting is just more branches to trace instead of one line to read..lower() wasn’t required but felt necessary. For the login check, comparing raw strings meant "Johnny123" would fail against "johnny123". Normalizing both sides with .lower() before comparing wasn’t in the spec, but it’s the kind of thing that matters the moment a real person types into the prompt.Comparators and booleans aren’t just for a single if — chaining and/or (or nesting conditionals to the same effect) is how you turn “is this true” into “is this specific combination of things true.” random.randint() and random.choice() cover two different needs: one picks a number in a range, the other picks an item from a list — useful to keep straight since they get reached for in different situations. And elif chains read better than deeply nested ifs once there are more than two or three outcomes to cover, which the login gatekeeper’s four cases made obvious.
Day 3 picks up lists and loops: creating and indexing lists, .append()/.remove()/del, the in operator, for loops, range(), sum(), and break.
int/float/str, input()/print(), type conversion, string concatenation, and comments. Three challenges, increasing difficulty: a warm-up, an applied script, and a mini-project.
1. Mad Libs Generator (warm-up) — collects a few words with input() and concatenates them into a silly sentence:
print("Welcome to Mad Libs!")
#adjective
adjective = input("Enter an adjective word: ")
#noun
noun = input("Enter a noun word: ")
#name of verb
verb = input("Enter a verb word: ")
#name of the animal
animal = input("Enter an animal word: ")
#print mad lib sentence
print("The " + adjective + " " + noun + " " + verb + " " + animal + "s")
2. Tip Calculator (applied) — splits a bill with tip across a group, using type conversion and formatted output:
#total bill
total_bill = float(input("Enter the total bill amount: "))
#total people splitting the bill
total_people = float(input("Enter the number of people splitting the bill: "))
#percentage of the tip
tip_percent = float(input("Enter the tip percent (e.g. 10, 15, or 20): "))
#total bill with tip
bill_plus_tip = total_bill + (total_bill * (tip_percent / 100))
#amount owe by each person
person_owe = bill_plus_tip / total_people
#print out the total bill and each person split
print(f"The total bill with tip is: {bill_plus_tip:.2f}")
print(f"Each person owes: {person_owe:.2f}")
3. Profile Card Generator (mini-project) — takes name, birth year, height, and weight, calculates current age, and prints a formatted summary card:
from datetime import datetime
#name
name = input("What is your name? : \n")
#birth year
birth_year = input("What is your birth year? : \n")
#height in cm
height = input("What is your height in cm? : \n")
#weight in kg
weight = input("What is your weight in kg? : \n")
age_now = int(datetime.now().year) - int(birth_year)
# printout the profile in multiline format
print(f"""
### Profile Card ###
Name: {name}
Birth Year: {birth_year}
Height: {height} cm
Weight: {weight} kg
Age now: {age_now}
""")
The tip calculator was the cleanest of the three — the input → calculate → output flow clicked fast. The rough edges showed up in the details:
float() or int() that were already the right type — e.g. float(bill_plus_tip / total_people) when dividing two floats already returns a float. Easy mistake, easy fix once it’s pointed out.birth_year gets converted because I need it for math, but height and weight stay as raw strings from input() since I only print them. It works, but it means I only practiced type conversion on the one field that forced my hand — something to be more deliberate about next time, even when a value isn’t immediately used in a calculation.input() always returns a string — no exceptions — so every number I want to do math with has to pass through int() or float() explicitly. F-strings with format specs like {value:.2f} are a clean way to control decimal output without manual rounding. And string concatenation with + works fine for short sentences, but gets noisy fast — f-strings scale better once there’s more than two or three pieces to stitch together.
Day 2 picks up conditionals, booleans, and the random module — if/elif/else, comparators, and/or/not, and importing modules for the first time.