PCAP Strings Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  [s for s in feedback if s.startswith('4') or s.startswith('5')]

  Why it's wrong here

  This comprehension selects entire feedback strings rather than extracting the comment portion, so it cannot return comments. The startswith() check also fails to isolate the rating precisely: a rating like '45' would pass because it starts with '4', and any leading whitespace would cause a valid rating to be ignored. It neither splits on the delimiter nor verifies the rating is exactly one of the allowed values.

• ✗

  [s.split(':') for s in feedback][1]

  Why it's wrong here

  This is a list comprehension that splits each item, producing a list of lists; the trailing [1] then indexes the outer list, not the second element of each split string. Thus it would return an entire split result (or raise an IndexError if the list is short) instead of the comment for every feedback. Additionally, there is no rating filter at all, so the expression is fundamentally unrelated to the task.

• ✓

  [s.split(':')[1].strip() for s in feedback if s.split(':')[0].strip() in ('4','5')]

  Why this is correct

  This is correct because it first splits the feedback string at the colon, strips whitespace from both the rating and comment, and only keeps the comment when the rating is exactly '4' or '5'. The condition uses a tuple membership test on the stripped first part, avoiding false positives from comments that merely contain the digit. It cleanly returns the comment portion, which is exactly what the requirement asks for.

• ✗

  [s.split(':')[1] for s in feedback if '4' in s or '5' in s]

  Why it's wrong here

  This filters on whether '4' or '5' appears anywhere in the entire feedback string, rather than checking the rating field specifically. As a result, a comment like 'I would not pay 5 dollars' would be included even if the rating is 1, and the extracted comment is not stripped, leaving unwanted whitespace. The correct logic must compare the first field to the allowed ratings, not probe the whole string for digits.