• 5.2.1 Accessing values

• 5.2.2 Adding new key-value pairs

• 5.2.3 Starting with an empty dictionary

• 5.2.4 Modifying values in a dictionary

• 5.2.5 Removing key-value pairs

• 5.2.6 A dictionary of similar objects

• 5.2.7 Using get() to access values safely

• 5.3.1 Looping through all key-value pairs (items)

• 5.3.2 Looping through all keys (keys)

• 5.3.3 Looping through keys in a specific order (sorted)

• 5.3.4 Looping through all values (values, set)

• 5.4.1 A list of dictionaries

• 5.4.2 A list in a dictionary

• 5.4.3 A dictionary in a dictionary

• 6.1.1 Writing clear prompts

• 6.1.2 Using int() to accept numerical input

• 6.1.3 The modulo operator

• 6.2.1 The while loop in action

• 6.2.2 Letting the user choose when to quit

• 6.2.3 Using a flag

• 6.2.4 Using break to exit a loop

• 6.2.5 Using continue in a loop

• 6.2.6 Avoiding infinite loops

• 6.3.1 Moving items from one list to another

• 6.3.2 Removing all instances of specific values from a list

• 6.3.3 Filling a dictionary with user input

1. Hash: compute hash('timmy') % 8 = 4.
1.

1. Jump: go directly to row 4 of the table.
2.

1. Verify: the stored hash matches hash('timmy'), and the stored key equals 'timmy'.
3.

1. Return: read the Value column of row 4 → 'red'.
4.

1. Hash: compute hash('timmy') % 8 = 4.
1.

1. Read the index table: indices[4] = 0 (a value of -1 means the key does not exist, so KeyError is raised immediately).
2.

1. Access the entries array: jump to row 0 of entries.
3.

1. Verify: the stored hash matches hash('timmy'), and the stored key equals 'timmy'.
4.

1. Return: entries[0].value → 'red'.
5.

favorite_languages = {
    'jen': 'python',
    'sarah': 'c',
    'edward': 'ruby',
    'phil': 'python',
}
print("Unique languages mentioned:")
for language in set(favorite_languages.values()):
    print(language.title())

Unique languages mentioned:
Ruby
C
Python

pizza = {
    'crust': 'thick',
    'toppings': ['mushrooms', 'extra cheese'],
}
print(f"You ordered a {pizza['crust']}-crust pizza with:")
for topping in pizza['toppings']:
    print(f" - {topping}")

You ordered a thick-crust pizza with:
 - mushrooms
 - extra cheese

server = {
    'hostname': 'auth-01',
    'open_ports': [22, 443, 8443]
}

users = {
    'aeinstein': {
        'first': 'albert',
        'last': 'einstein',
        'location': 'princeton',
    },
    'mcurie': {
        'first': 'marie',
        'last': 'curie',
        'location': 'paris',
    },
}
for username, user_info in users.items():
    print(f" Username: {username}")
    full_name = f"{user_info['first']} {user_info['last']}"
    print(f" Full name: {full_name.title()}")
    print(f" Location: {user_info['location'].title()}")

Username: aeinstein
Full name: Albert Einstein
Location: Princeton
Username: mcurie
Full name: Marie Curie
Location: Paris

prompt = "If you share your name, we can personalize the messages you see."
prompt += " What is your first name? "
name = input(prompt)
print(f" Hello, {name}!")

If you share your name, we can personalize the messages you see.
What is your first name? Eric
Hello, Eric!

number = input("Enter a number, and I'll tell you if it's even or odd: ")
number = int(number)
if number % 2 == 0:
    print(f" The number {number} is even.")
else:
    print(f" The number {number} is odd.")

Enter a number, and I'll tell you if it's even or odd: 42
The number 42 is even.

current_number = 0
while current_number < 10:
    current_number += 1
    if current_number % 2 == 0:
        continue
    print(current_number)

1
3
5
7
9

responses = {}
polling_active = True
while polling_active:
    name = input(" What is your name? ")
    response = input("Which mountain would you like to climb someday? ")
    responses[name] = response
    repeat = input("Would you like to let another person respond? (yes/ no) ")
    if repeat == 'no':
        polling_active = False
print(" --- Poll Results ---")
for name, response in responses.items():
    print(f"{name} would like to climb {response}.")

What is your name? Alice
Which mountain would you like to climb someday? Denali
Would you like to let another person respond? (yes/ no) no
--- Poll Results ---
Alice would like to climb Denali.

user_db = {'admin': 'SecretPass123!'}
failed_attempts = 0
MAX_FAILS = 3
while failed_attempts < MAX_FAILS:
    pwd = input("Enter password: ")
    if pwd == user_db['admin']:
        print("Authentication successful! Welcome.")
        failed_attempts = 0
        break
    else:
        failed_attempts += 1
        remaining = MAX_FAILS - failed_attempts
        print(f"Invalid password. Attempts remaining: {remaining}")
else:
    print("ALERT: Account locked due to excessive failed attempts.")

inventory = {}
while True:
    service_name = input("Enter service name (or 'quit' to finalize): ").strip().lower()
    if service_name == 'quit':
        break
    port_str = input(f"Enter port for {service_name}: ").strip()
    if not port_str.isdigit():
        print("Port must be numeric. Skipping entry.")
        continue
    port = int(port_str)
    protocol = input("Enter protocol (TCP/UDP): ").strip().upper()
    inventory[service_name] = {'port': port, 'protocol': protocol}
print(" --- Verified Service Inventory ---")
for svc, data in sorted(inventory.items()):
    print(f"Service: {svc.upper():<10} | Port: {data['port']:<5} | Protocol: {data['protocol']}")

--- Verified Service Inventory ---
Service: HTTPS | Port: 443 | Protocol: TCP
Service: SSH | Port: 22 | Protocol: TCP