Class 9 Computer Science — Looping over a list

1.Each of these loop headings has a single print inside it. Put them in order of how many numbers each one prints, fewest first.

• for n in [4, 9]:
• for n in [5, 5, 5, 5]:
• for n in [1, 2, 3]:
• for n in [2, 4, 6, 8, 10]:

2.The list this loop is given has nothing in it at all. What does the program print?

readings = []
total = 0
for r in readings:
    total = total + r
print(total)

• a) 0
• b) 1
• c) Nothing at all
• d) There is no way to tell

3.Two counters are kept at once here, and the last line compares them. What does the program print?

marks = [7, 3, 9, 2, 6]
passes = 0
fails = 0
for m in marks:
    if m > 5:
        passes = passes + 1
    else:
        fails = fails + 1
print(passes - fails)

4.One line of this program is inside the loop and one is outside it. How many numbers does it print altogether?

prices = [3, 6, 2]
total = 0
for p in prices:
    total = total + p
    print(p)
print(total)

5.The program below is run again with each of these lists written into its first line. Match each list to the number the loop counts.

values = [4, 5]
count = 0
for n in values:
    if n > 10:
        count = count + 1

6.The program below is run again with each of these lists written into its first line. Sort each list by the total the loop leaves behind.

values = [6, 6]
total = 0
for n in values:
    total = total + n

7.This loop does not add the values up. It counts how many of them pass a test. What does it print?

scores = [3, 8, 2, 9, 6]
count = 0
for s in scores:
    if s > 5:
        count = count + 1
print(count)

8.This one multiplies rather than adds, so what it starts from matters. What does it print?

sizes = [2, 3, 4]
product = 1
for s in sizes:
    product = product * s
print(product)