Ten additional coding tasks · W061–W070
Choose starters to try yourself, or download a separate worked example pack after attempting the tasks.
Chapter 7 starters ↓Chapter 7 worked examples ↓Print 1 through 5, not 1 through 4.
range stops before its upper bound.
# Try this incorrect version first, then compare with the fix:
# for n in range(1, 5):
# print(n)
for n in range(1, 6):
print(n)
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Calculate a three-score average rather than a total.
You must divide by the count.
# Try this incorrect version first, then compare with the fix:
# scores = [6, 9, 12]
# print(sum(scores))
scores = [6, 9, 12]
print(sum(scores) / len(scores))
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Ensure a score of exactly 50 passes.
Use the inclusive comparison.
# Try this incorrect version first, then compare with the fix:
# score = 50
# print("Pass" if score > 50 else "Retry")
score = 50
print("Pass" if score >= 50 else "Retry")
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Display the final element in a three-item list.
Length is not the final zero-based index.
# Try this incorrect version first, then compare with the fix:
# items = ["A", "B", "C"]
# print(items[len(items)])
items = ["A", "B", "C"]
print(items[len(items) - 1])
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Accept Yes, YES and yes as the same answer.
Convert to lowercase before comparing.
# Try this incorrect version first, then compare with the fix:
# answer = "YES"
# print(answer == "yes")
answer = "YES"
print(answer.lower() == "yes")
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Accumulate the entire list instead of resetting on every turn.
Initialise total before the loop.
# Try this incorrect version first, then compare with the fix:
# values = [2, 3, 4]
# for x in values:
# total = 0
# total += x
# print(total)
values = [2, 3, 4]
total = 0
for x in values:
total += x
print(total)
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Access requires BOTH helmet and glasses.
Use and, not or.
# Try this incorrect version first, then compare with the fix:
# helmet = True
# glasses = False
# print(helmet or glasses)
helmet = True
glasses = False
print(helmet and glasses)
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Append an item without replacing the list with None.
append() modifies in place and returns None.
# Try this incorrect version first, then compare with the fix:
# items = ["pen", "book"]
# items = items.append("ruler")
# print(items)
items = ["pen", "book"]
items.append("ruler")
print(items)
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Count down correctly from 4 to 1.
Use a negative step in range.
# Try this incorrect version first, then compare with the fix:
# for n in range(4, 0):
# print(n)
for n in range(4, 0, -1):
print(n)
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.
Calculate the £90 price after a 10% discount, not £9.
Multiply by 0.90 for a discounted price.
# Try this incorrect version first, then compare with the fix:
# price = 100
# print(price * 0.10)
price = 100
print(price * 0.90)
One possible solution. Try writing your own first.
Extension: Create two tests that would have caught this bug.