Question

What line of code should be written after the function definition to add two single-digit values and print the sum?

def get_single_digit():
while True:
try:
num = int(input("Enter a single-digit positive number: "))
if num > 9:
print("Number must be less than 10")
elif num < 0:
print("Number must be positive.")
else:
return num
except ValueError:
print("That isn't a number!")


print(get_single_digit() + get_single_digit())


return get_single_digit() + get_single_digit()


print(get_single_digit(4) + get_single_digit(5))


print(get_single_digit()++)

Question: 2
What will be printed when the program below is run?

def add_two(x):
return x + 2

def multiply_by_three(x):
return x * 3

def my_function(x):
return add_two(x) + multiply_by_three(x)

print(my_function(12))


12


24


50


66

Question: 3
What will be printed to the screen if the inputs given to the program below are 1.2, -4, hi, 5 ?

def retrieve_positive_number():
while True:
try:
number = int(input("Enter a positive number: "))
if number > 0:
return number
print("The number must be positive!")
except ValueError:
print("That wasn't a number!")

print(retrieve_positive_number())


Enter a positive number: 1.2
The number must be positive!
Enter a positive number: -4
The number must be positive!
Enter a positive number: hi
That wasn't a number!
Enter a positive number: 5
5

Enter a positive number: 1.2
That wasn't a number!
Enter a positive number: -4
That wasn't a number!
Enter a positive number: hi
That wasn't a number!
Enter a positive number: 5
5

Enter a positive number: 1.2
1.2

Enter a positive number: 1.2
That wasn't a number!
Enter a positive number: -4
The number must be positive!
Enter a positive number: hi
That wasn't a number!
Enter a positive number: 5
5
Question: 4
Which of the following programs will NOT cause an error?



say_hi("Margaret")

def say_hi(name):
print("hi " + name)

function say_hi(name):
print("hi " + name)

def say_hi(first_name="John", last_name="Doe"):
print("hi " + first_name + " " + last_name)

say_hi("Polly Pocket")

def say_hi(first_name="John", last_name):
print("hi " + first_name + " " + last_name)

say_hi(‘Polly’, ‘Pocket’)

Answer 1

Question 1
Answer: print(get_single_digit() + get_single_digit())
Reason: call the function twice and print the sum. `return` can't be used at top level, `get_single_digit(4)` passes invalid args, and `++` is not valid Python.

Question 2
Answer: 50
Reason: add_two(12)=14, multiply_by_three(12)=36, 14+36=50.

Question 3
Answer (what will be printed):
Enter a positive number: 1.2
That wasn't a number!
Enter a positive number: -4
The number must be positive!
Enter a positive number: hi
That wasn't a number!
Enter a positive number: 5
5

Question 4
Answer: Only the program with
def say_hi(first_name="John", last_name="Doe"):
print("hi " + first_name + " " + last_name)

say_hi("Polly Pocket")
Reason: default parameters after non-default is a syntax error and calling before a def/name or using `function` keyword are errors; the shown definition with two defaults is valid.