loops.py

1.
Question 1
Fill in the blanks of this code to print out the numbers 1 through 7.

1 / 1 point


number = 1
while number in range(1,8):
	print(number, end=" ")
	number +=1


  2.
Question 2
The show_letters function should print out each letter of a word on a separate line. Fill in the blanks to make that happen.

1 / 1 point

def show_letters(word):
  	for letter in word:
		print(letter)

show_letters("Hello")
# Should print one line per letter


3.
Question 3
Complete the function digits(n) that returns how many digits the number has. For example: 25 has 2 digits and 144 has 3 digits. Tip: you can figure out the digits of a number by dividing it by 10 once per digit until there are no digits left.

1 / 1 point

def digits(n):
  	count = 0
	if n == 0:
	  return 1
	while (n > 0):
		count += 1
		n = n//10
	return count
	
print(digits(25))   # Should print 2
print(digits(144))  # Should print 3
print(digits(1000)) # Should print 4
print(digits(0))    # Should print 1


4.
Question 4
This function prints out a multiplication table (where each number is the result of multiplying the first number of its row by the number at the top of its column). Fill in the blanks so that calling multiplication_table(1, 3) will print out:

1 2 3 

2 4 6 

3 6 9

1 / 1 point


def multiplication_table(start, stop):
  	for x in range(start, stop+1):
		for y in range(start, stop+1):
			print(str(x*y), end=" ")
		print()

multiplication_table(1, 3)
# Should print the multiplication table shown above


5.
Question 5
The counter function counts down from start to stop when start is bigger than stop, and counts up from start to stop otherwise. Fill in the blanks to make this work correctly.

1 / 1 point

def counter(start, stop):
  	x = start
	if start > stop:
		return_string = "Counting down: "
		while x >= stop:
			return_string += str(x)
			x-=1
			if x >= stop:
				return_string += ","
	else:
		return_string = "Counting up: "
		while x <= stop:
			return_string += str(x)
			x+=1
			if x <= stop:
				return_string += ","
	return return_string

print(counter(1, 10)) # Should be "Counting up: 1,2,3,4,5,6,7,8,9,10"
print(counter(2, 1)) # Should be "Counting down: 2,1"
print(counter(5, 5)) # Should be "Counting up: 5"


6.
Question 6
The even_numbers function returns a space-separated string of all positive numbers that are divisible by 2, up to and including the maximum that's passed into the function. For example, even_numbers(6) returns “2 4 6”. Fill in the blank to make this work.

1 / 1 point

def even_numbers(maximum):
  	return_string = ""
	for x in range(2, maximum+1, 2):
		return_string += str(x) + " "
	return return_string.strip()

print(even_numbers(6))  # Should be 2 4 6
print(even_numbers(10)) # Should be 2 4 6 8 10
print(even_numbers(1))  # No numbers displayed
print(even_numbers(3))  # Should be 2
print(even_numbers(0))  # No numbers displayed


.
Question 7
The following code raises an error when executed. What's the reason for the error?


def decade_counter():
	while year < 50:
		year += 10
	return year

1 / 1 point


Failure to initialize variables

Correct
Well done! The variable year needs to be initialized prior to being used in the while loop.


8.
Question 8
What is the value of x at the end of the following code?


for x in range(1, 10, 3):
    print(x)
1 / 1 point


7
Correct
You got it! The upper limit of a range isn’t included, which means that the loop stops before reaching it. The increment is 3, so the loop stops when x reaches 7.



9.
Question 9
What is the value of y at the end of the following code?


for x in range(10):
    for y in range(x):
        print(y)

1 / 1 point

8
Correct
Great job! The upper limit of a range isn’t included, which means that the outer loop goes up to 9, so the highest upper limit for the inner loop is 9, which is also not included.



10.
Question 10
How does this function need to be called to print yes, no, and maybe as possible options to vote for?


def votes(params):
	for vote in params:
	    print("Possible option:" + vote)

1 / 1 point


votes(['yes', 'no', 'maybe'])

Correct
Excellent! This function is looking for one argument, and the list of strings is just one argument.