About the Final Exam

CS 149, 05-Dec-2025

Format and Length

You've done this 12 times!

• See practice quizzes on CS-149-F25.
• See actual quizzes on Gradescope.
• Practice solving similar problems!

Tentative Outline

Q1. Evaluate Expressions

• Determine the type and value
• Arithmetic, logic, and containers

Q2. Trace Nested If-Else

def can_vote(age, registered):
    if registered:
        if age <= 0:
            message = "Input Error: Age is invalid!"
        elif age < 18:
            message = "You have to be at least 18 to vote!"
        else:
            message = "You are eligible to vote!"
    else:
        message = "You are not registered to vote!"
    return message

• What is the message? can_vote(15, True)
• What is the message? can_vote(18, False)

Q3. Trace For/While Loops

picks = (44, -17, 253)
for i, x in enumerate(picks):
    if x > 0:
        print(i, x, end=" ")

sci_fi = ("Interstellar",
    "Coherence", "Blade Runner")

a = 0
z = len(sci_fi) - 1
while a <= z:
    print(sci_fi[a])
    a += 3
print(a)

Q4. Assert Statements

Test every branch of the can_vote() function from Q2.

Format:
assert function_call(args) == expected_value

Q5. List/String Methods

s = "  Let's go Python!  "
w = s.split()[1].upper()
z = len(s.strip())

nums = list(range(4))
nums.insert(2, "Hi")
nums.pop()

Q6. Recursive Functions

def power(base, exp):
    if exp == 0:
        return 1
    else:
        return base * power(base, exp - 1)

power(2, 4)

• How many times is the power() function called?
• What is the return value of each function call?
• Give an example that causes a RecursionError.

Q7. Topics from Quiz 1-2

Statements, Expressions, Branches, Functions

Example: Write shipping_cost(weight) that takes the weight of a package and returns the shipping cost as a float.

• Packages up to 2 pounds cost $5
• Packages over 2 pounds and up to 6 pounds cost $10
• Packages over 6 pounds and up to 10 pounds cost $15
• Packages over 10 pounds cost $20

Q8. Topics from Quiz 3-4

Containers, While Loops, For Loops, Testing

Example: Write odd_words(words) that takes a list of strings and returns a set containing only the strings with an odd number of characters.

Q9. Topics from Quiz 5-6

Sequences, File I/O, Nested Data, Recursion

Example: Write word_lengths(path):

• Read a text file and count how many words of each length appear in the file.
• Return a dictionary where the keys are word lengths and the values are the number of words with that length.

Hello world
Python is fun

>>> word_lengths("sample.txt")
{5: 2, 6: 1, 2: 1, 3: 1}