Control Flow, Loops, Lists and Logic

A developer writes a loop to sum numbers from 1 to 10. The code outputs 55, but the expected sum is 55. However, the loop uses a range that includes 0. Which range should be used to achieve the correct sum?

A programmer needs to iterate over a list of strings and print each string in uppercase. Which loop correctly accomplishes this?

A programmer writes code that uses a while loop to process user input until the user types 'exit'. The code currently prints 'Done' after the loop, but it never exits. What is the most likely cause?

A list of numbers is defined as nums = [1, 2, 3, 4, 5]. Which expression returns the last element?

A list contains strings and numbers: items = ['apple', 10, 'banana', 20]. A programmer wants to create a new list that contains only the strings. Which approach is correct?

A developer writes the following code snippet: for i in range(3): for j in range(2): if i == j: break else: print(i, 'outer') What is the output?

A programmer needs to check if at least one element in a list of booleans flags is True. Which expression correctly does this?

Given the code: x = [1, 2, 3] y = x y.append(4) print(x) What is the output?

A programmer wants to create a list of even numbers from 0 to 10 inclusive. Which list comprehension is correct?

What is the output of the code?

A developer runs main.py and gets True. They then modify config.py by adding `allowed_ports.append(22)` and run main.py again without restarting the interpreter. What is the output?

Which TWO of the following are valid ways to create a list with elements 10, 20, 30?

Which TWO of the following code snippets will print the numbers 0, 1, 2, 3, 4?

Which THREE of the following are valid list operations?

You are working on a network automation script that reads a configuration file containing firewall rules. Each rule is a dictionary with keys 'source_ip', 'dest_ip', 'action'. The script must iterate over the rules and print all rules where action is 'allow'. However, the script is not printing any output even though there are allow rules in the file. The code snippet is: rules = [{'source_ip':'10.0.0.1','dest_ip':'10.0.0.2','action':'allow'}, {'source_ip':'10.0.0.2','dest_ip':'10.0.0.3','action':'deny'}] for rule in rules: if rule('action') == 'allow': print(rule) What is the most likely cause of the problem?

You are writing a script to parse a log file. Each line in the log contains a timestamp and a message separated by a colon. You need to extract only the messages that contain the word 'ERROR'. The script uses a list comprehension to filter lines. However, the script crashes with a 'ValueError: not enough values to unpack' when processing some lines. The code is: lines = ['2024-01-01 12:00:00: INFO: all good', '2024-01-01 12:01:00: ERROR: something wrong'] errors = [msg for timestamp, msg in line.split(': ') for line in lines if 'ERROR' in msg] What is the correct fix?

Arrange the steps to handle an exception in Python using try-except.

Arrange the steps to install a third-party Python package using pip.

Match each exception type to its description.

Match each Python concept to its description.

A junior developer needs to write code that processes a list of student scores and stops processing when a score of 100 is encountered, as that score represents a perfect score that should be treated separately. Which loop construct is most appropriate?

A data analyst has a list of temperature readings in Celsius and wants to create a new list containing only readings that are valid (>= -273.15 and <= 1000). Which code correctly creates the filtered list?

A developer is implementing a toggle switch feature. The variable flag starts as False. Which code snippet correctly toggles the flag and performs an action based on the new value each time the code is run? (Assume action1 is performed when flag is True, action2 when False.)

Which code correctly and efficiently sums only positive numbers from a list?

A developer needs to iterate over a list of network interfaces and print only the names that start with 'eth'. Which code should be used?

A programmer has a list of tuples representing (product, price) and wants to find the highest price. Which code correctly finds the maximum price?

Which code correctly creates a list of squares for numbers 1 to 5 using a list comprehension?

A developer needs to implement a loop that prints numbers from 10 down to 1. Which loop correctly achieves this?

A program contains a nested while loop. The inner loop should run as long as a condition is True, but the outer loop should stop after 3 iterations. Which code structure is correct? (Assume the inner loop condition is inner < 5.)

Which two of the following list methods modify the original list in place? (Choose two.)

Which two of the following expressions evaluate to True? (Choose two.)

Which three of the following statements about lists are true? (Choose three.)

Refer to the exhibit. What is the output?

Refer to the exhibit. What is printed?

Refer to the exhibit. What is the output?

A company maintains a list of employee names. They want to check if 'Alice' is in the list. Which of the following is the most Pythonic way to achieve this?

A developer writes a while loop to count down from 10 to 1 and then stop. Which condition should be used?

A team is reviewing code that uses if-elif-else to classify a test score. They notice that for score 90, it prints 'B' instead of 'A'. Which of the following best explains the issue?

A developer needs to write a loop that prints all even numbers from a list. They attempt: for num in numbers: if num % 2 == 0: print(num). However, they want a more efficient approach using list comprehension. Which alternative achieves the same result?

A company uses a for loop to iterate over a list of transaction amounts. They want to skip negative amounts. Which statement inside the loop correctly achieves this?

A developer writes: result = [x**2 for x in range(10) if x % 2 == 0]. What does this code produce?

A developer is troubleshooting a loop that terminates earlier than expected. The code is: i = 0; while i < 5: if i == 3: break; print(i); i += 1. What is the output?

A team observes that the following code prints 'Found' even when the item is not in the list. Code: for item in mylist: if item == target: print('Found'); break; else: print('Not found'). Which modification ensures it correctly prints 'Not found' only if the item is not present?

A developer writes a recursive function to compute factorial, but it causes a RecursionError. Which of the following is the most likely cause?

Which TWO of the following are valid ways to iterate over a list in reverse order? (Choose two.)

Which THREE statements about the break statement in Python are correct? (Choose three.)

Which TWO of the following code snippets will produce the output '0 1 2'? (Choose two.)

What is the output of the code?

What is the output of the code?

What is the output of the code?

Refer to the exhibit. What is the output?

Refer to the exhibit. What is printed?

Refer to the exhibit. What is the output?

How many times will the following loop print 'Hi'? for i in range(3): print('Hi')

Which loop is more efficient for iterating over a large list when you only need the values, not indices?

A company stores employee data as a list of dictionaries. Each dictionary has keys 'name' and 'age'. Which code correctly counts employees older than 30?

A program reverses a string using a while loop. The code is: text = "hello" reversed_text = "" index = len(text) - 1 while index > 0: reversed_text += text[index] index -= 1 print(reversed_text) It prints 'olle' instead of 'olleh'. What is the error?

A student grades system: score = 85 if score >= 90: grade = 'A' elif score >= 80: grade = 'B' elif score >= 70: grade = 'C' else: grade = 'F' What grade is assigned?

Which list method modifies the list in place by adding all elements of another iterable to the end?

A program uses a while loop to find the largest number in a list until a negative number is encountered. What is wrong with this code? numbers = [3, 7, 2, -1, 5] max_num = 0 i = 0 while numbers[i] >= 0: if numbers[i] > max_num: max_num = numbers[i] i += 1 print(max_num)

A developer wants to generate a list of squares of integers from 1 to 10 inclusive. Which list comprehension is correct?

A developer needs to check if all elements in a list of integers are even. Which code correctly implements this?

Which TWO of the following list operations modify the list in place?

Which THREE of the following are valid ways to iterate over a list?

Which TWO of the following are true about Python's if statement?

A company needs to filter a list of temperatures in Celsius to only those above 0, then convert to Fahrenheit (multiply by 9/5 and add 32). Which code snippet correctly accomplishes this using a list comprehension?

A developer writes code to iterate over a list and break when a certain condition is met. Which keyword is used to exit the loop prematurely?

A log file processing script uses a while loop to read lines until a specific pattern is found. The code currently hangs. The developer suspects an infinite loop. Which change is most likely to fix the issue?

A program needs to print the index and value of each item in a list named 'items'. Which code snippet correctly does this?

What is the output of the code? numbers = [1, 2, 3, 4] result = [x**2 for x in numbers if x % 2 == 0] print(result)

A network engineer writes a script to validate IP addresses. The script checks each octet and prints 'Valid' if all octets are between 0 and 255, otherwise 'Invalid'. However, the script always prints 'Invalid' for valid IPs. The code uses a for loop with an else clause. Which logical error is likely?

Which of the following best describes the behavior of the 'range' function in a for loop?

What does the following code print? x = 10 if x > 5: if x > 15: print("A") else: print("B") else: print("C")

A developer is writing a function that takes a list of numbers and returns the sum of all even numbers. Which two code snippets correctly implement this function? (Select two.)

Which two of the following are valid ways to create a list with elements 1, 2, 3? (Select two.)

A developer is debugging a function that uses a while loop to reverse a list in place. The current code causes an infinite loop. Which three modifications would likely fix the infinite loop? (Select three.)

A system administrator is writing a Python script to monitor server uptime. The script reads a log file line by line, parses timestamps, and stores them in a list. It then loops through the list to detect gaps longer than 5 minutes that indicate a crash. However, the script keeps missing crashes. The current loop is a for loop that iterates over the list using indices. The administrator suspects the loop logic. The loop uses 'for i in range(len(timestamps)-1): if timestamps[i+1] - timestamps[i] > 300: print("Crash detected")'. Timestamps are integers representing seconds since epoch. What is the most likely cause of missed crashes and the best fix?

A data analyst is processing a large dataset of customer transactions. The dataset is stored as a list of dictionaries, each with keys 'amount' and 'date'. The analyst needs to compute the total revenue for 2024. They write: total = 0 for t in transactions: if t['date'].year == 2024: total += t['amount'] They then run it and get a KeyError: 'date'. After inspection, they notice that some records have a 'Date' key (capital D) instead. The analyst wants to fix this without modifying the data. Which approach will correctly sum amounts regardless of key case?

A developer is writing a simple number guessing game. The computer picks a random number between 1 and 100, and the user keeps guessing until correct. The developer implements: secret = random.randint(1,100) guess = 0 while guess != secret: guess = int(input("Guess: ")) if guess == secret: print("Correct!") else: print("Wrong, try again.") The game works, but the developer notices that if the user enters something that is not an integer, the program crashes. Which modification ensures the program handles non-integer input gracefully?

A network administrator uses a Python script to analyze firewall logs. The script reads a CSV file with columns 'src_ip', 'dst_ip', 'action', 'time'. It needs to build a list of source IPs that have been blocked more than 3 times. The current code: blocked_count = {} blocked_ips = [] for row in logs: if row['action'] == 'block': if row['src_ip'] in blocked_count: blocked_count[row['src_ip']] += 1 else: blocked_count[row['src_ip']] = 1 for ip, count in blocked_count.items(): if count > 3: blocked_ips.append(ip) The script runs correctly but slowly on large logs. The administrator wants to optimize it. Which change would most improve performance?

Which two of the following statements about Python lists are true?

A junior developer writes a Python script to sum all numbers greater than 10 from a list. The code is: numbers = [5, 12, 8, 15, 3] total = 0 for num in numbers: if num > 10: total = total + 1 print(total) The output is 2, but the expected sum is 27 (12+15). Which change will produce the correct output?

A data analyst writes a Python script to double each element in a matrix without altering the original. The code is: original = [[1,2,3],[4,5,6]] copy = original for i in range(len(original)): for j in range(len(original[i])): copy[i][j] *= 2 print(original) The output shows [[2,4,6],[8,10,12]], meaning the original was also changed. Which single modification to the line 'copy = original' ensures the original matrix remains unchanged?

Refer to the exhibit. What is the final value of x after executing the code?

Refer to the exhibit. Why does the code successfully remove all even numbers but the output is [1, 3, 5]?

Refer to the exhibit. What does the else clause of the inner for loop do?

Refer to the exhibit. What is the output of the code?

Refer to the exhibit. What is the final value of my_list?