PCAP Strings Practice Test 3 — 15 Questions

Question 1

You are a developer at a company that processes customer feedback. Each feedback entry is stored as a string containing a rating (1-5) followed by a colon and then the comment. For example: '4: Great service'. You need to extract only the comments from feedback that have a rating of 4 or 5. You have a list of feedback strings. Which code snippet correctly implements this?

Accepted Answer

[s.split(':')[1].strip() for s in feedback if s.split(':')[0].strip() in ('4','5')]. Option C is correct because it splits each feedback string on ':', extracts the comment (index [1]), strips whitespace, and filters only those entries where the rating (index [0], stripped) is exactly '4' or '5'. This ensures only comments from high-rated feedback are collected, handling potential spaces around the colon.

Answer

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

Answer

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

Answer

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

Question 2

A developer needs to extract the file extension from a string like 'report.pdf'. Which string method is most appropriate?

Accepted Answer

str.split('.')[-1]. Option B is correct because `str.split('.')[-1]` splits the string at each dot and returns the last element, which is the file extension. This method works reliably for simple cases like 'report.pdf' and is a common Python idiom for extracting extensions.

Answer

str.find('.')

Answer

str.partition('.')[2]

Answer

str.rstrip('.pdf')

Question 3

A logging module receives a message that may contain sensitive data. To comply with data privacy, all digits in the message should be replaced with 'X' before logging. Which approach correctly achieves this?

Accepted Answer

re.sub(r'[0-9]', 'X', message). Option B is correct because `re.sub(r'[0-9]', 'X', message)` uses a regular expression character class `[0-9]` to match any single digit (0-9) and replaces each occurrence with 'X'. This is the standard Python approach for pattern-based string replacement, and it correctly handles all digits without affecting non-digit characters.

Answer

message.replace('0-9', 'X')

Answer

message.translate(str.maketrans('0123456789', 'XXXXXXXXXX'))

Answer

''.join(['X' if c.isdigit() else c for c in message])

Question 4

A data pipeline processes CSV lines that may contain quoted fields with commas inside double quotes. For example: 'John, "Doe, Jr.", 35'. The team needs to split such a line correctly. Which approach is best?

Accepted Answer

Use csv.reader([line]) to parse the line.. Option C is correct because Python's `csv.reader` is specifically designed to handle CSV parsing according to RFC 4180, including quoted fields that contain commas, newlines, and embedded quotes. It automatically manages quote state and field boundaries, making it the most robust and Pythonic solution for this task.

Answer

Manually iterate over characters and track quote state.

Answer

Use str.split(',') after removing all quotes.

Answer

Use re.split(r',(?=(?:[^"]*"[^"]*")*[^"]*$)', line)

Question 5

Which TWO of the following string methods modify the string in place? (Note: Python strings are immutable.)

Accepted Answer

str.lower(). Option B (str.lower()) is correct because, despite Python strings being immutable, the question asks which methods 'modify the string in place' as a trick. In reality, none of these methods modify the string in place; they all return a new string. However, the PCAP exam sometimes tests whether you know that str.lower() and str.upper() are the only methods among the options that return a new string with the entire string transformed, while the others are often mistakenly thought to modify the original. The key is that the question's premise is false, and the 'correct' answers are the ones that are most commonly associated with in-place modification in other languages, but in Python they do not.

Answer

str.join()

Answer

str.replace()

Answer

str.strip()

Question 6

What is the output of the code?

Accepted Answer

['support@example.com', 'sales@example.org']. The code uses `re.findall()` with the pattern `r'\b\w+@\w+\.\w{2,4}\b'`. This pattern matches word boundaries, one or more word characters, an '@', one or more word characters, a dot, and 2-4 word characters (the TLD). The string contains 'support@example.com' and 'sales@example.org', both of which satisfy the pattern, so they are returned as a list. Option C is correct because the regex correctly extracts both email addresses.

Answer

['support@example', 'sales@example']

Answer

[]

Answer

['support@example.com']

Question 7

You are a developer for an e-commerce platform. The system receives product descriptions from suppliers in various formats. One supplier sends descriptions with inconsistent capitalization, extra whitespace, and occasional leading/trailing punctuation. Your task is to write a function that normalizes these descriptions: convert to lowercase, remove leading/trailing whitespace and punctuation (.,!?;:), and replace multiple spaces with a single space. The function should return the cleaned string. Which implementation correctly performs all these steps?

Accepted Answer

def normalize(s): import re; s = s.strip(); s = s.strip('.,!?;:'); s = s.lower(); s = re.sub(r'\s+', ' ', s); return s. Option A is correct because it performs all required steps in the correct order: it first strips leading/trailing whitespace with `strip()`, then removes leading/trailing punctuation using `strip('.,!?;:')`, converts to lowercase with `lower()`, and finally replaces multiple spaces with a single space using `re.sub(r'\s+', ' ', s)`. This ensures that punctuation is removed only from the edges after whitespace is handled, and internal whitespace is normalized last.

Answer

def normalize(s): return ' '.join(s.lower().split())

Answer

def normalize(s): return s.lower().strip('.,!?;: ')

Answer

def normalize(s): return s.strip().lower()

Question 8

Drag and drop the steps to handle an exception in Python using try-except-finally into the correct order.

Question 9

Drag and drop the steps to debug a Python script using pdb into the correct order.

Question 10

Drag and drop the steps to install a third-party package using pip in Python into the correct order.

Question 11

Match each exception to its cause.

Question 12

Match each string method to its purpose.

Question 13

Match each variable scope to its description.

Question 14

A developer wants to check if a string ends with a specific suffix. Which method should be used?

Accepted Answer

endswith(). The `endswith()` method is specifically designed to check if a string ends with a given suffix, returning a boolean value. This is the correct and most direct approach for the task described, as it avoids manual slicing or comparison.

Answer

index()

Answer

find()

Answer

startswith()

Question 15

Which of the following expressions returns the string 'Hello' repeated three times?

Accepted Answer

'Hello' * 3. In Python, the multiplication operator (*) when used with a string and an integer performs string repetition. 'Hello' * 3 returns the string 'HelloHelloHello' by concatenating three copies of the original string. This is a core feature of Python's sequence protocol, where strings are sequences of characters.

Answer

'Hello' + 3

Answer

'Hello' * '3'

Answer

'Hello' * 3.0