Our 3-Week Project Journey

Week 3 (Today): Foundation

• Variables and basic data
• Control flow (if/else)
• Loops for repetition
• String manipulation
• Simple contact storage

Week 4: Power Features

• Functions for organization
• Lists and dictionaries
• File save/load
• Professional structure

Week 6: Going Pro

• Classes and objects
• Error handling
• Debugging techniques

Let's build something real!

Project Setup: Simple Contact Storage

# contact_manager_v1.py
# Week 3: Building the foundation

print("="*40)
print("  CONTACT MANAGER v0.1 (Basic)")
print("="*40)

# We'll build this step by step!

Follow along - create this file now!

Part 1: Storing Contact Data

Variables for One Contact

# Store a single contact's information
# TODO: Create variables for:
# - contact_name (string)
# - contact_phone (string)  
# - contact_age (integer)
# - is_favorite (boolean)

# TODO: Print a welcome message using the contact's name

# TODO: Calculate and print their age next year

Try it yourself first!

Getting User Input

# Let's make it interactive!
print("\n--- Add New Contact ---")

# TODO: Get contact information from user
# Remember: input() always returns a string!

contact_name = input("Enter contact name: ")
# TODO: Get phone number
# TODO: Get age (hint: convert to int!)
# TODO: Ask if favorite (y/n)

# TODO: Display the contact info nicely

Common mistake: Forgetting to convert input to numbers!

Building a Contact Display

# Format contact information nicely
contact_name = "Alice Smith"
contact_phone = "555-0001"
contact_age = 25
is_favorite = True

# TODO: Create a formatted display string
# Should look like:
# =====================================
# Contact: Alice Smith
# Phone: 555-0001
# Age: 25 years old
# Favorite: Yes
# =====================================

# Hint: Use string concatenation or f-strings

Part 2: Making Decisions

Add Contact Validation

# Validate contact information before storing
contact_name = input("Enter name: ")
contact_phone = input("Enter phone: ")

# TODO: Check if name is not empty
# If empty, print error and set to "Unknown"

# TODO: Check if phone has at least 7 digits
# If too short, print warning

# TODO: Only mark as valid contact if both checks pass

Real programs validate input!

Contact Categories with If/Elif/Else

# Categorize contacts by age
contact_age = int(input("Contact's age: "))

# TODO: Determine category:
# - Under 18: "Minor"
# - 18-30: "Young Adult"
# - 31-60: "Adult"
# - Over 60: "Senior"

# TODO: Print category and special notes
# E.g., "Minor - Requires parental consent"

Think about the order of conditions!

Menu System with Conditions

print("\n--- Contact Manager Menu ---")
print("1. Add contact")
print("2. View contact")
print("3. Exit")

choice = input("\nChoose option: ")

# TODO: Use if/elif/else to handle menu choices
# - If "1": Print "Adding contact..."
# - If "2": Print "Viewing contact..."
# - If "3": Print "Goodbye!"
# - Else: Print "Invalid option!"

This is the start of our interface!

Part 3: Storing Multiple Contacts

Using Loops for Multiple Contacts

# Store up to 3 contacts
max_contacts = 3
contact_count = 0

print(f"\nYou can add up to {max_contacts} contacts")

# TODO: Use a while loop to:
# - Keep asking for contacts until max_contacts reached
# - Or until user types "done"
# - Track how many contacts added

# TODO: After loop, print summary
# "Added X contacts to your manager"

Display All Contacts with For Loop

# Simulate having 3 contacts
# (Next week we'll use lists for this!)
contact1_name = "Alice"
contact2_name = "Bob"
contact3_name = "Charlie"

print("\n--- All Contacts ---")

# TODO: Use a for loop with range(3) to:
# - Print contact number (1, 2, 3)
# - Print contact name
# Format: "Contact #1: Alice"

# Hint: You'll need if/elif to pick the right variable

Preview: Lists will make this much easier!

Search Contacts with String Methods

# Search for a contact
contact1_name = "Alice Smith"
contact2_name = "Bob Jones"
contact3_name = "Charlie Smith"

search_term = input("Search for: ")

# TODO: Check each contact name
# - Convert both to lowercase for case-insensitive search
# - Use 'in' to check if search_term is in name
# - Print matching contacts

# Example: Searching for "smith" finds Alice and Charlie

Part 4: String Formatting

Format Contact Cards

# Create nice contact cards
name = "Alice Smith"
phone = "555-0001"
age = 25

# TODO: Create a contact card using f-strings:
# ╔════════════════════════════╗
# ║  CONTACT CARD              ║
# ║  Name: Alice Smith         ║
# ║  Phone: 555-0001           ║
# ║  Age: 25                   ║
# ╚════════════════════════════╝

# Hint: Use f-strings for formatting
# card = f"Name: {name}"

Make it look professional!

String Operations for Contacts

contact_name = "  alice SMITH  "
contact_phone = "5550001"

# TODO: Clean up the contact data:
# - Remove extra spaces with strip()
# - Capitalize name properly with title()
# - Format phone as "555-0001"

# TODO: Validate the cleaned data:
# - Check if name has at least 2 characters
# - Check if phone has exactly 7 digits

Clean data is happy data!

Build a Complete Mini Contact Manager

# Put it all together!
print("\n" + "="*40)
print("  CONTACT MANAGER v0.1")
print("="*40)

running = True
contact_count = 0
max_contacts = 3

while running:
    # TODO: Show menu
    # TODO: Get user choice
    # TODO: Handle each option:
    #   1. Add contact (if not at max)
    #   2. View all contacts
    #   3. Search contacts
    #   4. Exit
    
    pass  # Remove this when you add code

print("Thank you for using Contact Manager!")

This is your Week 3 project!

Challenge: Add Features

Enhance your Contact Manager:

1. Contact Counter: Show "X of 3 contacts used"

2. Duplicate Check: Don't add same name twice

3. Phone Formatting: Auto-format as XXX-XXXX

4. Favorite Marking: Mark contacts with

5. Statistics: Show total contacts, favorites count

Try these on your own!

What We Built Today

Contact Manager v0.1

Features implemented:

• Store contact information
• Input validation
• Menu system
• Add multiple contacts
• Search by name
• Display all contacts
• Nice formatting

Skills learned:

• Variables and data types
• User input
• If/else decisions
• Loops (for and while)
• String manipulation
• Basic program structure

Next week: We'll make it powerful with functions and lists!

Homework: Practice Assignment

Problem Set Week 3: Git & Python Fundamentals

GitHub Classroom Link:
https://classroom.github.com/a/ibuQ6b6G

Practice problems to complete:

1. Git Workflow: Practice commits and pushes
2. Temperature Converter: Functions and calculations
3. Number Analysis: Control flow and loops
4. File Word Counter: String processing

This is ungraded practice - focus on learning!

Tips:

• Start with the Git workflow problem
• Test your code frequently
• Commit your progress often
• Ask for help on Discord if stuck!

Pro Tips from Week 3

1. Start simple

# Build step by step, test each part

2. Use meaningful names

# Bad: n, p, a
# Good: contact_name, phone_number, age

3. Validate input

# Always check user input before using it

4. Test edge cases

# What if user enters nothing?
# What if they enter invalid data?

Remember: Every expert was once a beginner!