Class 9 Computer Science — Building a list as you go

1.Only some of the counter's values get into this list. What does the program print?

found = []
for n in range(1, 8):
    if n * n > 20:
        found.append(n)
print(found[0])

• a) 5
• b) 6
• c) 25
• d) 4

2.One loop sits inside another here, and the appending is in the deeper of the two. What does the program print?

pairs = []
for a in range(0, 3):
    for b in range(0, 4):
        pairs.append(a + b)
print(len(pairs))

• a) 3
• b) 4
• c) 12
• d) 7

3.This program appends four values. Put them in the order they end up sitting in the list, the front of the list first.

made = []
for n in range(2, 6):
    made.append(n * n)

• 9
• 25
• 16
• 4

4.Look hard at the range before working anything else out. How many values does this list end up with?

empty = []
for n in range(5, 5):
    empty.append(n)
print(len(empty))

5.This program starts with an empty list and puts one value into it each time round. How many values does it end up with?

squares = []
for n in range(1, 5):
    squares.append(n * n)
print(len(squares))

6.A running total is appended each time round here, so the list holds the totals rather than the values. What does the program print?

totals = []
running = 0
for n in range(1, 5):
    running = running + n
    totals.append(running)
print(totals[3])

7.This one prints the value that ended up at the front of the list. What does it print?

squares = []
for n in range(1, 6):
    squares.append(n * n)
print(squares[0])

8.There are two appends inside this loop rather than one. How many values does the list end up with?

names = []
for n in range(1, 4):
    names.append(n)
    names.append(n * 10)
print(len(names))