Most Frequently Asked Python Interview Questions

Here are some of the most frequently asked Python interview questions and brief answers:

What is Python?
Python is a high-level, interpreted, general-purpose programming language that is widely used for web development, scientific computing, data analysis, artificial intelligence, and more.

Why is Python popular for data science and scientific computing?
Python is popular for data science and scientific computing due to its simplicity, readability, and a vast library of data science and scientific computing packages like NumPy, Pandas, Matplotlib, and others.

What are the advantages and disadvantages of using Python?
Advantages include its simplicity, ease of use, readability, and a vast library of packages. Disadvantages include its dynamic typing system, which can lead to runtime errors, and performance issues compared to lower-level programming languages.

How is Python different from other programming languages?
Python is different from other programming languages in its simplicity and readability, as well as its vast library of packages for data science, scientific computing, and other domains.

How can you write a simple “Hello, World!” program in Python?
print(“Hello, World!”)

How to use if else statement in Python?
The if-else statement is used to control the flow of the program based on a certain condition. For example:
if condition:
# execute this block if condition is True
else:
# execute this block if condition is False

What is a Python list and how to create it?
A Python list is an ordered collection of items that can be of different data types. It is defined using square brackets, for example: list = [1, 2, 3, 4, 5].

What is the difference between a tuple and a list in Python?
The main difference between a tuple and a list in Python is that a tuple is immutable, meaning its elements cannot be changed after creation, whereas a list is mutable, meaning its elements can be changed.

How to use loops in Python?
Loops in Python allow us to repeat a block of code multiple times. The two main types of loops in Python are for loops and while loops.

What is the use of the ‘break’ and ‘continue’ statements in loops?
The break statement is used to exit a loop early, before its normal termination. The continue statement is used to skip the current iteration of the loop and move on to the next iteration.

How to define and call a function in Python?
A function in Python is defined using the def keyword, followed by the function name, parameters, and a colon. For example:
def my_function(param1, param2):
# function code here
The function can be called using its name and passing the required parameters.

What is a dictionary in Python and how to use it?
A dictionary in Python is an unordered collection of key-value pairs, where each key is unique. It is defined using curly brackets, for example: dict = {‘key1’: ‘value1’, ‘key2’: ‘value2’}.

What is a set in Python and how to use it?
A set in Python is an unordered collection of unique elements. It is defined using curly brackets or the set() constructor, for example: set = {1, 2, 3, 4, 5}. Sets can be used to perform set operations like union, intersection, difference, etc.

What is a module in Python and how to create and use it?
A module in Python is a file containing Python definitions and statements. It can be created by creating a new .py file and defining functions, classes, and variables. Modules can be used to reuse code and make the code more organized. A module can be imported and used in another .py file by using the import statement, for example: import my_module.

What is the use of the ‘try-except’ block in Python?
The try-except block in Python is used to handle exceptions that may occur in the code. The code that may raise an exception is placed inside the try block, and the code to handle the exception is placed inside the except block. For example:
try:
# code that may raise an exception
except ExceptionType:
# code to handle the exception

What is a decorator in Python and how to use it?
A decorator in Python is a special type of function that is used to modify the behavior of another function. Decorators are applied to functions using the @decorator_name syntax, for example:
def my_decorator(func):
def wrapper():
# code to modify the behavior of func
func()
return wrapper

@my_decorator
def my_function():
# original function code here

How to handle errors and exceptions in Python?
Errors and exceptions in Python can be handled using the try-except block or by using the raise statement to raise an exception explicitly.

How to handle file I/O in Python?
File I/O in Python can be done using the built-in open() function, which returns a file object. The file object can be used to read from or write to a file. For example, to open a file for reading:
file = open(‘file.txt’, ‘r’)
data = file.read()
file.close()
To write to a file:

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file = open(‘file.txt’, ‘w’)
file.write(‘data to write’)
file.close()

What is the use of the ‘with’ statement in Python?
The with statement in Python is used to manage resources, such as file objects, by automatically closing the resource after it has been used. For example:
with open(‘file.txt’, ‘r’) as file:
data = file.read()
In this example, the file is automatically closed after the with block is exited.

What are the differences between Python 2 and Python 3?
Some of the main differences between Python 2 and Python 3 include changes to the print statement, division operator, exception handling, and text handling.