Computer Programming and Python Fundamentals

You are a junior developer at a logistics company. Your team maintains a Python script that processes daily shipment data from a CSV file. The script reads the file, computes total weight per shipment, and writes results to a new CSV. Recently, the script started crashing sporadically with a 'ValueError: invalid literal for int() with base 10: 'NULL''. The CSV file sometimes contains the string 'NULL' in the weight column for missing values. The current code reads the weight column as: weight = int(row['weight']). Your team lead wants a robust fix that handles missing data gracefully without crashing, and also logs the line number for any problematic rows for later review. Which of the following approaches best meets these requirements?

A program uses a for loop to double each element in a list: numbers = [1, 2, 3, 4, 5]; for num in numbers: num = num * 2. After execution, numbers remains unchanged. Why?

Arrange the steps to read data from a text file in Python.

What does the following code print? text = 'Hello World'; print(text.replace('o', '0').upper())

You are a developer in a company that runs a Python script daily to generate reports. The script uses the os module to list files in a directory and process each. Recently, after a server migration, the script fails with 'PermissionError: [Errno 13] Permission denied'. The script runs under a service account that has read/write access to most folders, but the migration changed the permissions on certain subdirectories. The error is intermittent, occurring only for some files. You need to fix the script to continue processing other files even if one fails. Which approach should you take?

Refer to the exhibit. What is the most likely cause of this error?

A programmer needs a constant that identifies the maximum number of retry attempts for a network operation. The value must not change while the program runs. Which statement about naming and using this constant in Python is accurate?

Which two of the following are true about Python lists? (Choose two.)

What does the following code output? for i in range(3): if i == 1: continue; print(i, end=' ')

Consider code: def outer(): x = 1 def inner(): nonlocal x x = 2 inner() print(x) outer() What is printed?

A junior developer is writing a script to process a list of user IDs: ids = [101, 102, 103, 104]. The goal is to create a new list where each ID is increased by 10, without modifying the original list. The developer writes: new_ids = ids.append(10). However, the output shows None. The developer needs to correctly create the new list. Which code should the developer use to achieve this?

A developer writes code to calculate the area of a rectangle and prints it. The code is: length = 10 width = 5 area = length + width print('The area is', area) If the width is accidentally assigned a string '5', what error will occur?

A developer is writing a Python script and needs to create valid variable names. Which two of the following are valid variable names? (Choose two.)

A programmer wants to iterate over a list of strings and print each string in uppercase. Which of the following code snippets will accomplish this?

A trainee is reviewing how Python 3 handles basic data types and type conversion in a small inventory script. Which TWO statements about Python's built-in numeric and string types are correct? (Choose two.)

A beginner writes: x = 10; y = 3; print(x // y). What is the output?

Which THREE of the following are correct ways to create a list containing the numbers 1, 2, 3? (Choose three.)

A Python program contains the following code: print(10 / 4) What is displayed when this program runs?

A junior developer is working on a script that processes user data. The script reads a CSV file into a list of dictionaries. Each dictionary represents a user with keys 'name', 'age', and 'email'. The developer needs to filter out users under 18 and store their names in a list. The current code is: users = [{'name': 'Alice', 'age': 17, 'email': 'alice@example.com'}, {'name': 'Bob', 'age': 22, 'email': 'bob@example.com'}] minors = [] for user in users: if user['age'] < 18: minors.append(user['name']) print(minors) The code works, but the senior developer says it is not idiomatic and suggests a more concise solution. Which of the following approaches is the best replacement?

Which THREE of the following statements about Python data types are correct? (Choose three.)

A developer needs to iterate over the indices of a list named 'items' and print each index and its corresponding value. Which loop construct is most appropriate?

A developer wrote: a, b, c = 10, 20, 30; avg = a + b + c / 3; print(avg). What is the output?

A developer is reviewing how literals and operators behave in a Python script. Which TWO of the following statements about Python literals and operators are true? (Choose two.)

A Python developer is creating a function that processes a list of dictionaries and needs to ensure the original list remains unchanged. They write the following code: def process(data): for item in data: item['processed'] = True return data What is the best-practice critique of this function?

A Python program is designed to process user input and store results in a dictionary. The code uses the statement: my_dict[user_key] = value. Under which condition will this statement raise a TypeError?

A developer writes a short script to convert a numeric string entered at the console into a number for arithmetic: value = input('Enter a quantity: ') total = value * 2 print(total) A user types 7 and presses Enter. What is printed, and why?

You are an IT support specialist for a university. A professor uses a Python script that analyzes exam scores from a text file. The script calculates the average score and prints it. Recently, the script outputs 'NaN' instead of a number. The relevant code is: scores = [float(line.strip()) for line in open('scores.txt')]; average = sum(scores) / len(scores); print(average). You inspect the scores.txt file and find that one line contains the word 'Absent' and another line is blank. The professor wants the script to ignore non-numeric lines and blank lines, and also print a warning if any line was skipped. Which of the following modifications to the script best achieves this?

A developer writes a function that calculates the area of a rectangle and prints the result inside the function. Later, they need to use this area in another calculation. What should they do to make the function reusable and composable?

Which logical expression evaluates to True given that a = 5 and b = 10?

A developer writes the following code: x = 5 if x > 3: print('A') else: print('B') print('C') What is the output?

Which TWO of the following are valid variable names in Python?

A programmer is writing a Python script to calculate the area of a circle. They write the following code: radius = 5 area = 3.14 * radius ** 2 print(area) What is the output of this code?

Match each Python keyword to its use.

Refer to the exhibit. Which of the following is true about the output?

A developer writes the following code and runs it without any error: x = 5 y = 2.0 z = x + y What is the value and type of z?

A junior developer is writing a script to read a number from input and double it. They write: num = input("Enter a number: ") result = num * 2 print(result) When they test with input 5, the output is '55' instead of 10. What is wrong?

A function is defined as: def add(a, b=5): return a + b What is the result of add(10)?

What is the output?

A developer is writing a Python script and assigns a value to a variable named '2nd_place'. When the script is run, it raises a SyntaxError. What is the cause of this error?

You are a junior developer at a small startup. Your team has a Python script that automates daily data processing. The script reads a CSV file, processes each row, and writes results to a new file. Recently, the script started crashing with a 'ValueError: invalid literal for int()' error. The error occurs on a line that converts a field to an integer using int() on a string value. The CSV file comes from an external source that sometimes contains non-numeric values like 'N/A' or empty strings. Which course of action is best to handle this robustly without stopping the entire process?

You are maintaining a Python script that calculates team bonuses based on sales data. The script reads a dictionary where keys are employee names and values are total sales (float). It then applies a 10% bonus if sales exceed 5000. The code snippet is: def calculate_bonus(sales): for name, value in sales.items(): if value > 5000: print(f"{name} gets bonus") However, the manager wants the script to return a list of employees who qualify, not just print them. They also want to avoid side effects. What is the best way to modify this function?

Match each Python data type to its description.

A Python program needs to store the integer value 42 in a variable named count. Which line of code correctly assigns this value?

Which THREE of the following are valid ways to create a list in Python?

According to PEP 8, which of the following is the recommended way to name a constant representing the maximum number of retries?

A Python script calculates the area of a circle: radius = 5; area = 3.14 * radius ** 2; print(area). What is printed?

A QA engineer needs to run a test 5 times. Which loop construct is most appropriate?

You are a developer on a team that maintains a legacy Python 2 codebase being migrated to Python 3. One function reads a file in text mode and counts word frequencies. In Python 2, the code used the dict.iteritems() method to iterate over the dictionary. After migration, the code raises AttributeError: 'dict' object has no attribute 'iteritems'. You need to update the code to work in Python 3 while minimizing changes. Which action should you take?

A developer needs to check if a number is positive and even. Which conditional expression is correct?

A dictionary: d = {1: 'a', 2: 'b', 3: 'c'}. Which code will cause a KeyError?

A developer writes a function that modifies a global variable inside the function: count = 0 def increment(): count += 1 When called, an error occurs. What is the correct way to fix this?

An application requires different messages based on temperature. Given: temp = 25 if temp > 30: print('Hot') elif temp > 20: print('Warm') else: print('Cool') What is the output?

Which THREE of the following are valid ways to create a list with elements 1, 2, 3? (Choose Three)

A programmer needs to read a file line by line and process each line. Which of the following is the most memory-efficient and Pythonic approach?

A function is supposed to modify a list passed as argument by appending an element. However, after calling the function, the original list remains unchanged. Which is the most likely cause?

A student runs the following code in a Python 3.11 interactive session: >>> 7 // 2 What is displayed?

A team is developing a script that processes user input. They want to ensure that if the user enters a non-numeric value when asked for age, the program does not crash. Which approach should they use?

A script uses 'import math' then calls 'math.sqrt(-1)'. What is the outcome?

Which TWO of the following statements about Python's for loop are correct? (Choose Two)

Which of the following code snippets will correctly assign the integer 10 to the variable 'x'?

A program uses a variable named 'list' that shadows the built-in list type. Later, the code tries to create a new list using list([1,2,3]) but gets a TypeError. What is the most likely cause?

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

A programmer writes the following code to convert a user's input to a number and add 5: age = input('Enter age: ') new_age = int(age) + 5 print(new_age) If the user enters 'twenty', what happens?

Which TWO of the following are immutable data types in Python?

A programmer is debugging a Python script that is supposed to concatenate a user's first and last names with a space between them. The code is: first = 'John' last = 'Doe' full = first + ' ' + last print(full) What is the output of this script?

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

A developer runs the code from the exhibit and gets the error shown. Which of the following is the most likely cause?

A programmer is writing a Python script and needs to create variables that hold a user's name, age, and whether they are a student. Which TWO of the following assignments are syntactically valid and will execute without error in Python? (Choose two.)

A developer writes: print('Hello' + 5). What is the result?

A programmer wants to create a function that can accept any number of keyword arguments and store them in a dictionary. Which function definition is correct?

A programmer writes: x = 10 y = 4 print(x // y, x % y, x / y) What is printed?

A Python script processes a large file and runs out of memory. Which solution is most appropriate?

A developer writes a loop to find the first even number in a list: numbers = [3, 5, 8, 10] for n in numbers: if n % 2 == 0: print(n) break else: print('No even number') What is printed?

A developer defines a function and calls it as shown: def greet(name, greeting='Hello'): return greeting + ', ' + name print(greet('Ana')) What is printed?

A developer wants to store a collection of unique employee IDs that will be checked frequently for membership. Duplicate IDs must be automatically ignored, and the order of IDs does not matter. Which built-in data type best fits this requirement?

Which THREE of the following are Python data types? (Choose three.)

A Python script contains the following code: x = 10 y = 3 result = x // y What is the value of result after execution?

A programmer needs to store the number of items in a shopping cart. The value will be a whole number and may be used in arithmetic operations. Which Python data type is most appropriate for this variable?

Which TWO of the following are valid Python variable names? (Choose two.)

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

The exhibit shows a JSON configuration. Which Python data structure is best suited to represent this configuration?

Consider the code: x = 10; def func(): x = 5; print(x); func(); print(x). What is the output?

A developer writes a function that returns multiple values. How should they return these values?

Consider the following function definition: def add(a, b): return a + b What is the value of add(3, '4')?

Which of the following is the correct way to define a function that takes no arguments and returns the value 42?

A programmer writes: x = 5; y = 2; result = x / y. What is the type of result?

What function is used to read input from the user in Python 3?

Which of the following statements about Python indentation is true?

A developer writes the following code to sum a list of scores: scores = [12, 7, 25, 18] total = 0 for s in scores: total += s print(total) What is printed?

A programmer writes the following code to classify a temperature reading: temp = 25 if temp > 30: print('Hot') elif temp > 20: print('Warm') else: print('Cool') What is printed when this code runs?

Given the code: my_list = [1, 2, 3, 4, 5]. What is the output of print(my_list[-3:-1])?

A junior developer writes a Python script to calculate the average of three numbers: avg = a + b + c / 3. What is the problem with this code?

Which TWO statements correctly describe Python's dynamic typing?

A student types the following into a Python 3 interactive session: >>> greeting = 'Hello' >>> greeting = greeting + ' World' >>> print(greeting) What is displayed?

Which TWO statements about Python lists are true?

Which of the following is an immutable data type in Python?

A system administrator is automating server configuration using Python. She has a dictionary: config = {'host': 'localhost', 'port': 8080, 'debug': True}. She needs to add a new key 'timeout' with value 30 if it does not already exist, but only if the 'debug' key is False. If 'debug' is True, she should not add 'timeout'. Additionally, she wants to ensure that the ordering of keys in the dictionary remains stable (insertion order). Which code snippet correctly implements this logic?

A programmer wants to iterate over a list and also access the index. Which built-in function should they use?

What is the result of the following expression? 3 + 4 * 2 ** 3 // 5

Which THREE of the following code snippets will successfully print the string 'Hello, World!'? (Choose three.)

What will be printed? ```python my_list = [] my_list.append('192.168.1.10') my_list.append('255.255.255.0') my_list.append('192.168.1.1') print(my_list) ```

What is the output of the following code? print('Hello'.upper())

Which of the following is a floating-point literal?

A junior developer writes the following code to swap two variables: a = 5; b = 10; a = b; b = a. When they print a and b, what is the output?

A developer wants to create a list of even numbers from 0 to 10 inclusive. Which code snippet will correctly produce [0, 2, 4, 6, 8, 10]?

Which keyword is used to define a function in Python?

A developer is writing a Python script that stores the number of active user sessions in a variable. They want the variable to hold the value 42 as an integer. Which of the following statements correctly assigns the integer 42 to a variable named session_count?

A developer writes: try: x = int('hello') except ValueError: x = 0 except TypeError: x = -1 finally: x = x + 1 What is the final value of x?

What is the output of the following code? try: print(1/0); except ZeroDivisionError: print('error'); finally: print('done')

A programmer is debugging a Python script that uses a while loop to process a list of numbers. The code is: numbers = [1, 2, 3, 4, 5] i = 0 while i < len(numbers): if numbers[i] % 2 == 0: print(numbers[i]) i += 1 What is the output of this code?

Arrange the steps to slice a list in Python.

A Python program prompts the user for their age and stores it in a variable. Which is the correct way to convert the input to an integer?

A developer is reviewing Python's built-in numeric types while preparing a data-processing script. Which TWO statements about Python's numeric types are accurate? (Choose two.)

Which two of the following are correct ways to create a dictionary in Python? (Choose two.)

Arrange the steps to write and run a Python script from the command line in the correct order.

What is the output of: print(2 ** 3 ** 2)?

What is the scope of a variable defined inside a function?

A developer is reviewing a script that processes user data. The script contains the following lines: name = "Alice" age = 30 print(name + " is " + age) When executed, the script raises a TypeError. Which of the following changes will make the script run without error and produce the output "Alice is 30"?

A developer is writing a Python script to compare two numbers. They write the following code: x = 10 y = 20 result = x > y or x < y and y > 15 print(result) What is printed?

A developer writes the following code: values = [10, 20, 30, 40, 50] result = values[1:4] What does the variable result contain after execution?

What is the result of the expression: (1 and 0) or (not False and True)?

A developer is creating a Python script and needs to assign a value to a variable. Which TWO of the following assignment statements are syntactically valid in Python? (Choose two.)