Python Practice Set: Functions (Related Questions)

Test your knowledge on defining functions, using arguments, return values, and scope.

1. Conceptual Questions

Q1: What is the difference between print() and return inside a function?

Answer: print() simply displays a value on the console but doesn't "give" it back to the program. return sends a value back to the caller, allowing it to be stored in a variable or used in further calculations.

Q2: What is "Scope" in Python functions?

Answer: Scope determines where a variable can be accessed. A variable created inside a function is local (only accessible inside that function). A variable created outside a function is global (accessible everywhere).

Q3: Predict the output:

def my_func(x):
    x = x + 5
    return x

val = 10
my_func(val)
print(val)

Output: 10 (Note: The variable val outside the function remains unchanged because Python passes values, and x inside the function is a local copy)

2. Arguments & Parameters

Q4: What happens if you call a function with fewer arguments than it expects?

Answer: Python will raise a TypeError unless the missing parameters have default values defined in the function signature.

Q5: When should you use *args and **kwargs?

Answer: Use *args when you want a function to accept a variable number of positional arguments (received as a tuple). Use **kwargs for a variable number of keyword arguments (received as a dictionary).

Q6: Predict the output:

def greet(name, msg="Good morning!"):
    print(f"Hello {name}, {msg}")

greet("Tanis", "How are you?")
greet("Alice")

Output: Hello Tanis, How are you? Hello Alice, Good morning!

3. Lambda Functions

Q7: What is a Lambda function?

Answer: A small, anonymous function defined without a name using the lambda keyword. It can have any number of arguments but only one expression. Example: square = lambda x: x * x

4. Coding Challenges

Task 1: Check for Palindrome

Write a function is_palindrome(s) that returns True if a string is a palindrome and False otherwise.

def is_palindrome(s):
    s = s.lower().replace(" ", "")
    return s == s[::-1]

print(is_palindrome("Madam")) # True
print(is_palindrome("Python")) # False

Task 2: Factorial using Recursion

Write a recursive function to find the factorial of a number.

def factorial(n):
    if n == 1 or n == 0:
        return 1
    else:
        return n * factorial(n - 1)

print(factorial(5)) # Output: 120

Task 3: Sum of Arbitrary Numbers

Write a function that takes any number of arguments and returns their sum.

def sum_all(*args):
    return sum(args)

print(sum_all(1, 2, 3, 4, 5)) # Output: 15