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.

• ✓

  Use re.search(r'\bexcellent\b', review, re.IGNORECASE)

  Why this is correct

  The \b word boundary anchors ensure that 'excellent' is matched only when it stands as its own word, not as a substring of a larger token, while the re.IGNORECASE flag makes the match case-insensitive. Because re.search scans the entire string but the boundary restricts the match position, this option correctly finds 'Excellent', 'excellent.', and 'excellent' while rejecting 'unexcellent'. This is the only approach that combines whole-word semantics with case-insensitive matching in a single call.

• ✗

  Use 'excellent' in review.lower().split()

  Why it's wrong here

  This membership test lowercases the review and splits on whitespace, which sounds sensible until punctuation breaks the assumption: a token like 'excellent!' or '(excellent)' retains the punctuation and therefore will not equal the literal string 'excellent'. Split() only tokenizes on whitespace, not on punctuation, so real-world sentences with commas, periods, or exclamation marks produce false negatives. The test also relies on exact whole-token equality, which is brittle and fails on compound forms that regex \b handles flawlessly.

• ✗

  Use review.lower().count('excellent') > 0

  Why it's wrong here

  The count() method returns the number of non-overlapping occurrences of the substring, so the expression count('excellent') > 0 is both a misuse of counting semantics and a source of false positives. For example, the word 'unexcellent' contains the substring 'excellent' inside it, making the condition True even though 'excellent' is not a standalone word. This option ignores lexical boundaries entirely; it operates on raw character sequences and cannot distinguish between a word occurrence and a substring occurrence.

• ✗

  Use review.lower().find('excellent') != -1

  Why it's wrong here

  find() returns the index of the first occurrence of the literal substring anywhere in the string, so it reports success for cases like 'inexcellent' or 'excellent' embedded in a longer token, producing the same false positive as count() but via index arithmetic. The comparison against -1 is a common pattern, but the deeper flaw is that substring matching does not respect word boundaries, so it also matches within inflected forms or compound words. Unlike split(), find() never tokenizes and treats the string as a flat character sequence, making it unsuitable for whole-word searches.