[2024] Python Interview Questions for Beginners

Prepare for your Python job interview with these essential beginner-level Python interview questions. Explore fundamental concepts, coding practices, and key topics to boost your confidence and excel in Python programming interviews. Suitable for entry-level positions and Python enthusiasts looking to enhance their interview skills.

Python Interview Q & A Aug 27, 2024 205 Add to Reading List

[2024] Python Interview Questions for Beginners

Preparing for a Python interview can be both exciting and challenging, especially for beginners. To help you get ready, we've compiled a list of common Python interview questions specifically tailored for those who are just starting their journey in Python programming. Understanding and practicing these questions will give you a solid foundation for your interviews.

1. What is Python, and what are its key features?

Python is a high-level, interpreted programming language known for its readability and simplicity. Key features include:

Readability: Python’s syntax is designed to be clear and easy to read.
Interpreted: Python code is executed line by line.
Dynamically Typed: No need to declare variable types explicitly.
Object-Oriented: Supports object-oriented programming paradigms.
Extensive Libraries: Comes with a vast standard library and third-party packages.

2. How do you install Python on your system?

To install Python:

Download: Visit the official Python website and download the installer for your operating system.

Run Installer: Execute the downloaded file and follow the installation instructions. Be sure to check the option to add Python to your system’s PATH.

Verify Installation: Open a terminal or command prompt and type python --version to check the installed version.

3. How do you write and run a simple Python program?

To write and run a simple Python program:

Write Code: Open a text editor and write the following code:

print("Hello, World!")

Save the file with a .py extension, e.g., hello.py.

Run Program: Open a terminal or command prompt, navigate to the directory where your file is saved, and run:

python hello.py

4. What are variables in Python, and how are they used?

Variables are used to store data that can be referenced and manipulated in a program. In Python, variables are created by assigning a value to a name:

Example:

name = "Alice"
age = 25

5. Explain the difference between a list and a tuple in Python.

List: An ordered, mutable collection of items. Lists are defined with square brackets. Example:

fruits = ["apple", "banana", "cherry"]

Tuple: An ordered, immutable collection of items. Tuples are defined with parentheses. Example:

coordinates = (10, 20)

6. How do you create a function in Python?

Functions in Python are defined using the def keyword followed by the function name and parentheses. You can pass parameters and return values.

Example:

def greet(name):
    return f"Hello, {name}!"

print(greet("Alice"))

7. What are control structures in Python? Give examples.

Control structures in Python control the flow of execution. Common control structures include:

If-Else Statements: Used for conditional execution.

if age > 18:
    print("Adult")
else:
    print("Minor")

For Loops: Used for iterating over sequences.

for i in range(5):
    print(i)

While Loops: Used for repeated execution as long as a condition is true.

count = 0
while count < 5:
    print(count)
    count += 1

8. How do you handle exceptions in Python?

Exceptions are handled using try, except, else, and finally blocks. This mechanism helps manage errors and ensures the program runs smoothly.

Example:

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero.")
else:
    print("Division successful.")
finally:
    print("Execution completed.")

9. What are Python’s built-in data types?

Python includes several built-in data types:

int: Integer numbers.
float: Floating-point numbers.
str: Strings.
list: Ordered, mutable collections.
tuple: Ordered, immutable collections.
set: Unordered collections of unique items.
dict: Unordered collections of key-value pairs.

Example:

integer = 10
floating = 3.14
string = "Hello"
list_data = [1, 2, 3]
tuple_data = (1, 2, 3)
set_data = {1, 2, 3}
dict_data = {"key": "value"}

10. How do you use list comprehensions in Python?

List comprehensions provide a concise way to create lists. They consist of an expression followed by a for clause, and optionally, one or more if clauses.

Example:

squares = [x**2 for x in range(10)]
print(squares)  # [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

11. What are Python’s string methods?

Python strings come with a variety of built-in methods that allow for manipulation and querying. Some common methods include:

upper(): Converts all characters in a string to uppercase.

text = "hello"
print(text.upper())  # "HELLO"

lower(): Converts all characters in a string to lowercase.

text = "HELLO"
print(text.lower())  # "hello"

strip(): Removes whitespace from the beginning and end of a string.

text = "  hello  "
print(text.strip())  # "hello"

split(): Splits a string into a list of substrings based on a delimiter.

text = "apple,banana,cherry"
print(text.split(","))  # ["apple", "banana", "cherry"]

replace(): Replaces occurrences of a substring with another substring.

text = "hello world"
print(text.replace("world", "Python"))  # "hello Python"

12. How do you concatenate and repeat strings in Python?

Concatenation: Combine strings using the + operator.

greeting = "Hello"
name = "Alice"
message = greeting + " " + name
print(message)  # "Hello Alice"

Repetition: Repeat strings using the * operator.

echo = "Hello! " * 3
print(echo)  # "Hello! Hello! Hello! "

13. How do you check if a key exists in a dictionary?

You can check if a key exists in a dictionary using the in keyword.

Example:

my_dict = {"name": "Alice", "age": 25}
if "name" in my_dict:
    print("Key exists!")
else:
    print("Key does not exist.")

14. What is a lambda function, and how do you use it?

A lambda function is an anonymous, small function defined with the lambda keyword. It can have any number of arguments but only one expression.

Example:

# A lambda function that adds two numbers
add = lambda x, y: x + y
print(add(5, 3))  # 8

15. How do you create a class in Python?

Classes in Python are created using the class keyword. They allow for object-oriented programming by bundling data and methods together.

Example:

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def greet(self):
        return f"Hello, my name is {self.name} and I am {self.age} years old."

person = Person("Alice", 30)
print(person.greet())  # "Hello, my name is Alice and I am 30 years old."

16. What are Python’s built-in functions for type conversion?

Python provides several built-in functions to convert between different data types:

int(): Converts a value to an integer.

num = int("10")
print(num)  # 10

float(): Converts a value to a floating-point number.

num = float("10.5")
print(num)  # 10.5

str(): Converts a value to a string.

text = str(100)
print(text)  # "100"

list(): Converts a value to a list.

items = list("hello")
print(items)  # ['h', 'e', 'l', 'l', 'o']

tuple(): Converts a value to a tuple.

items = tuple([1, 2, 3])
print(items)  # (1, 2, 3)

17. How do you access elements in a list or tuple?

Lists: Access elements using indices starting from 0.

my_list = [10, 20, 30]
print(my_list[1])  # 20

Tuples: Access elements similarly to lists.

my_tuple = (10, 20, 30)
print(my_tuple[2])  # 30

Negative Indices: Access elements from the end using negative indices.

print(my_list[-1])  # 30
print(my_tuple[-2])  # 20

18. What are Python’s data structures, and how do they differ?

Python’s primary data structures include:

Lists: Ordered, mutable collections of items.
Tuples: Ordered, immutable collections of items.
Sets: Unordered collections of unique items.
Dictionaries: Unordered collections of key-value pairs.

Examples:

# List
my_list = [1, 2, 3, 4]

# Tuple
my_tuple = (1, 2, 3, 4)

# Set
my_set = {1, 2, 3, 4}

# Dictionary
my_dict = {"a": 1, "b": 2}

19. How do you perform list slicing in Python?

List slicing allows you to access a subset of elements from a list using the colon : operator.

Example:

numbers = [0, 1, 2, 3, 4, 5]
print(numbers[1:4])  # [1, 2, 3]
print(numbers[:3])   # [0, 1, 2]
print(numbers[3:])   # [3, 4, 5]
print(numbers[::2])  # [0, 2, 4]

20. How do you use the `range()` function in Python?

The range() function generates a sequence of numbers, commonly used in loops.

Example:

for i in range(5):
    print(i)
# Output: 0, 1, 2, 3, 4

You can also specify a start and stop, and an optional step value.

Example:

for i in range(1, 10, 2):
    print(i)
# Output: 1, 3, 5, 7, 9

21. What is the difference between `==` and `is` in Python?

==: Checks for value equality. Two objects are considered equal if their values are the same.

a = [1, 2, 3]
b = [1, 2, 3]
print(a == b)  # True

is: Checks for identity equality. Two objects are considered identical if they occupy the same memory location.

a = [1, 2, 3]
b = [1, 2, 3]
print(a is b)  # False (different memory locations)

22. How do you merge two lists in Python?

You can merge lists using the + operator or the extend() method.

Example:

list1 = [1, 2, 3]
list2 = [4, 5, 6]

# Using +
merged_list = list1 + list2
print(merged_list)  # [1, 2, 3, 4, 5, 6]

# Using extend()
list1.extend(list2)
print(list1)  # [1, 2, 3, 4, 5, 6]

23. What are Python decorators, and how do they work?

Decorators are a way to modify or extend the behavior of functions or methods without changing their definition. They are applied using the @ syntax.

Example:

def my_decorator(func):
    def wrapper():
        print("Something is happening before the function.")
        func()
        print("Something is happening after the function.")
    return wrapper

@my_decorator
def say_hello():
    print("Hello!")

say_hello()

24. How do you iterate over a dictionary in Python?

You can iterate over a dictionary’s keys, values, or key-value pairs using .keys(), .values(), and .items() methods, respectively.

Example:

my_dict = {"name": "Alice", "age": 25}

# Iterating over keys
for key in my_dict.keys():
    print(key)

# Iterating over values
for value in my_dict.values():
    print(value)

# Iterating over key-value pairs
for key, value in my_dict.items():
    print(f"{key}: {value}")

25. What is list slicing, and how do you use it?

List slicing allows you to extract parts of a list using the syntax [start:stop:step]. It returns a new list containing the specified slice.

Example:

numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
slice1 = numbers[2:5]  # [2, 3, 4]
slice2 = numbers[:4]   # [0, 1, 2, 3]
slice3 = numbers[5:]   # [5, 6, 7, 8, 9]
slice4 = numbers[::2]  # [0, 2, 4, 6, 8]

26. How do you use the `input()` function in Python?

The input() function is used to take input from the user. It reads a line from the input and returns it as a string.

Example:

name = input("Enter your name: ")
print(f"Hello, {name}!")

27. What are Python's `strip()`, `lstrip()`, and `rstrip()` methods?

strip(): Removes whitespace from both ends of a string.

text = "  hello  "
print(text.strip())  # "hello"

lstrip(): Removes whitespace from the beginning of a string.

text = "  hello  "
print(text.lstrip())  # "hello  "

rstrip(): Removes whitespace from the end of a string.

text = "  hello  "
print(text.rstrip())  # "  hello"

28. What is a Python `set`, and how is it different from a list?

A Python set is an unordered collection of unique items. Unlike lists, sets do not allow duplicate elements and do not maintain order.

Example:

my_set = {1, 2, 3, 4, 5}
my_set.add(6)
my_set.remove(3)

print(my_set)  # {1, 2, 4, 5, 6}

29. How do you perform mathematical operations in Python?

Python supports various mathematical operations including addition, subtraction, multiplication, division, and more.

Examples:

a = 10
b = 5

add = a + b          # 15
subtract = a - b     # 5
multiply = a * b     # 50
divide = a / b       # 2.0
modulo = a % b       # 0
power = a ** b       # 100000

30. What are Python list methods, and how do you use them?

Python lists come with several methods to modify and interact with them:

append(): Adds an item to the end of the list.

my_list = [1, 2, 3]
my_list.append(4)

remove(): Removes the first occurrence of a value.

my_list.remove(2)

pop(): Removes and returns an item at a given index.

my_list.pop()  # Removes the last item
my_list.pop(0) # Removes the item at index 0

sort(): Sorts the list in place.

my_list.sort()

reverse(): Reverses the list in place.

my_list.reverse()

31. How do you create and use modules in Python?

Modules are Python files with a .py extension that contain functions, classes, and variables. You can import them into other Python scripts.

Example:

Create a module (mymodule.py):

def greet(name):
    return f"Hello, {name}!"

Import and use the module:

import mymodule
print(mymodule.greet("Alice"))

32. How do you handle multiple exceptions in Python?

You can handle multiple exceptions by specifying multiple except blocks or using a tuple.

Example:

try:
    x = 1 / 0
except (ZeroDivisionError, ValueError):
    print("An error occurred.")

33. What are Python’s built-in functions for working with iterables?

Python provides several built-in functions to work with iterables:

len(): Returns the length of an iterable.

length = len([1, 2, 3])

sorted(): Returns a sorted list of the specified iterable.

sorted_list = sorted([3, 1, 2])

sum(): Returns the sum of all items in an iterable.

total = sum([1, 2, 3])

min() and max(): Return the smallest and largest items in an iterable.

minimum = min([1, 2, 3])
maximum = max([1, 2, 3])

34. How do you use the `zip()` function in Python?

The zip() function combines multiple iterables element-wise into tuples.

Example:

names = ["Alice", "Bob", "Charlie"]
ages = [25, 30, 35]

combined = list(zip(names, ages))
print(combined)  # [("Alice", 25), ("Bob", 30), ("Charlie", 35)]

35. How do you use the `map()` function in Python?

The map() function applies a given function to all items in an iterable.

Example:

numbers = [1, 2, 3, 4]

def square(x):
    return x ** 2

squared_numbers = list(map(square, numbers))
print(squared_numbers)  # [1, 4, 9, 16]

Conclusion

These Python interview questions for beginners cover the foundational concepts and practices necessary for a successful start in Python programming. Mastering these basics will help you gain confidence and demonstrate your readiness for entry-level Python roles. Continue practicing and exploring more advanced topics to enhance your skills and stand out in interviews.