A data analyst is writing a function that processes a list of numbers and returns a new list with each number squared. However, the function must not modify the original list. Which implementation is correct and follows best practices?

def square_list(numbers): for i in range(len(numbers)): numbers[i] = numbers[i] ** 2 return numbers

def square_list(numbers): return [n ** 2 for n in numbers]

def square_list(numbers): result = [] for n in numbers: result.append(n ** 2) return result

def square_list(numbers): return map(lambda x: x ** 2, numbers)

A data analyst has a list of dictionaries, each representing a product with keys 'id', 'name', and 'price'. They need to find the product with the highest price. Which code snippet is most efficient and correct?

sorted(products, key=lambda p: p['price'])[-1]

max(products, key=lambda p: p.get('price', 0))

max(products, key=lambda p: p['price'])

max(products, key=lambda p: p['price'])['name']

A data analyst is writing a script that uses pandas and numpy. They want to ensure that the script runs correctly regardless of the current working directory. Which best practice should they follow?

Change the current working directory at the start of the script using os.chdir() to a hardcoded path.

Use absolute file paths or construct paths relative to the script's location using __file__.

Use the os.path.join() function with a hardcoded base path.

Use relative file paths like 'data.csv'.

A data analyst has a list of numbers and needs to compute the sum of all even numbers. They also need to handle the case where the list is empty, returning 0. Which code snippet is both correct and Pythonic?

sum(n for n in numbers if n % 2 == 0)

sum([n for n in numbers if n % 2 == 0])

total = 0 for n in numbers: if n % 2 == 0: total += n

sum(filter(lambda x: x % 2 == 0, numbers))

Python InstitutePCAD - Certified Associate in Data Analytics with Python

Domain 2Objective 1

Core Python Proficiency PCAD-31 Practice Questions (Page 8)

Part of the Programming and Database Skills domain, which accounts for 33.3% of the PCAD-31 exam. Python Institute does not publish an official question count, but from its 60-minute exam (~25–40 total, ~8–8 in this domain), expect 2–2 from this objective — we provide 50 practice questions to prepare you well beyond it. (estimate)

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10free pages

5concepts

33.3%of the exam

Questions 36–40

36expert · medium
A data analyst is writing a function that processes a list of numbers and returns a new list with each number squared. However, the function must not modify the original list. Which implementation is correct and follows best practices?
Select an answer first
37expert · medium
A data analyst has a list of dictionaries, each representing a product with keys 'id', 'name', and 'price'. They need to find the product with the highest price. Which code snippet is most efficient and correct?
Select an answer first
38expert · medium
A data analyst is writing a script that uses pandas and numpy. They want to ensure that the script runs correctly regardless of the current working directory. Which best practice should they follow?
Select an answer first
39expert · medium
A data analyst has a list of numbers and needs to compute the sum of all even numbers. They also need to handle the case where the list is empty, returning 0. Which code snippet is both correct and Pythonic?
Select an answer first
40expert · easy
A data analyst is using a Jupyter notebook and wants to ensure that plots are displayed inline. They have already imported matplotlib.pyplot as plt. Which magic command should they run?
Select an answer first

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