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1. What does this program print? ``

python
xs = ['a', 'b', 'c', 'd', 'e']
for s in xs:
    if s == 'd':
        xs.remove(s)
print(xs)

``

2. What does this program print? ``

python
nums = [10, 15, 20, 25, 30]
i = 0
while i < len(nums):
    if nums[i] % 10 == 0:
        del nums[i]
    else:
        i += 1
print(nums)

``

[10, 20, 30][15, 20, 25]RuntimeError is raised[15, 25]

3. The loop below is meant to remove every 'Ben' from the list. What is the bug? ``

python
names = ['Ana', 'Ben', 'Ben', 'Dev']
for n in names:
    if n == 'Ben':
        names.remove(n)
print(names)

``

== should be is, so the strings are compared by identityAfter each removal the loop skips the item that moved into the removed spot, so the second 'Ben' survives. Loop over a copy, such as for n in names[:], or build a new list.Python raises RuntimeError at remove(), because the list changed while the loop was using itremove() takes an index, not a value, so it must be del names[n]

4. This loop is meant to remove the even numbers from a list. What happens when it runs? ``

python
v = [1, 2, 3, 4, 5]
for i in range(len(v)):
    if v[i] % 2 == 0:
        del v[i]
print(v)

``

It prints [1, 3, 5]It prints [1, 3, 4, 5]It raises IndexError: list index out of range, at v[i], because range(len(v)) was fixed at 5 when the loop started and the list got shorterIt prints [1, 3, 5] and works, because del moves the loop index back by one

5. The loop below removes people younger than 30. Where is the error raised, when the program fails? ``

python
ages = {'Ana': 31, 'Ben': 25}
for name in ages:
    if ages[name] < 30:
        del ages[name]

``

Inside the del statement, at the moment the key is removedInside the dict literal that created agesInside the < comparisonInside the next step of the loop, which compares the size the dict had when the loop started with its current size

Iterators and changing a list while looping