Python Interview Questions: A Comprehensive Guide for Aspirants
Python
is one of the most popular programming languages today, widely used for web
development, data analysis, artificial intelligence, machine learning, and
more. If you're preparing for a Python-based job interview, it's crucial to
familiarize yourself with both basic and advanced concepts. This guide covers
frequently asked Python interview questions to help you excel. Question in w3 school
 |
| PYTHON INTERVIEW QUESTIONS |
1. Basic Python Interview Questions
Q1.
What is Python? List some key features.
Answer:
Python is a high-level, interpreted programming language known for its
simplicity and readability.
Key
Features:
- Easy to Learn:
Python has a simple syntax similar to English.
- Dynamically Typed:
No need to declare data types explicitly.
- Interpreted:
Python code is executed line-by-line, which makes debugging easier.
- Extensive Libraries:
Python has rich libraries like NumPy, Pandas, and Matplotlib.
- Platform Independent:
Python can run on different platforms such as Windows, Linux, and Mac.
- Object-Oriented:
Supports OOP principles like inheritance, encapsulation, and polymorphism.
Q2.
What are Python’s data types?
Answer:
Python has the following standard data types:
- Numeric Types:
int, float, complex
- Sequence Types:
list, tuple, range
- Text Type:
str
- Set Types:
set, frozenset
- Mapping Type:
dict
- Boolean Type:
bool
- Binary Types:
bytes, bytearray, memoryview
Q3.
Explain Python’s list, tuple, and set with examples.
Answer:
- List:
Ordered, mutable, and allows duplicate elements.
Example:
my_list
= [1, 2, 3, 4, 5]
print(my_list[2]) # Output: 3
- Tuple:
Ordered, immutable, and allows duplicate elements.
Example:
my_tuple
= (1, 2, 3, 4, 5)
print(my_tuple[2]) # Output: 3
- Set:
Unordered, mutable, and does not allow duplicate elements.
Example:
my_set
= {1, 2, 3, 4, 5}
print(3
in my_set) # Output: True
2. Intermediate Python Interview
Questions
Q4.
What are Python decorators?
Answer:
Decorators are functions that modify the functionality of another function or
method. They are used to wrap another function and extend its behavior without
modifying its structure.
Example:
def
decorator_function(func):
def wrapper():
print("Before the function
call")
func()
print("After the function
call")
return wrapper
@decorator_function
def
say_hello():
print("Hello!")
say_hello()
Q5.
Explain Python’s Global Interpreter Lock (GIL).
Answer:
The Global Interpreter Lock (GIL) is a mutex that protects access to Python
objects, ensuring that only one thread executes Python bytecode at a time. This
simplifies memory management in CPython but limits multi-threading performance
in CPU-bound processes.
Q6.
How does Python handle memory management?
Answer:
Python handles memory management through:
- Automatic Garbage Collection:
Removes unused objects to free memory.
- Reference Counting:
An object is destroyed when its reference count drops to zero.
- Memory Pools:
Python uses private heaps for memory allocation.
Q7.
Explain list comprehension with an example.
Answer:
List comprehension is a concise way to create lists using a single line of
code.
Example:
squares
= [x**2 for x in range(10)]
print(squares) # Output: [0, 1, 4, 9, 16, 25, 36, 49, 64,
81]
3. Advanced Python Interview Questions
Q8.
What are Python generators?
Answer:
Generators are functions that return an iterator and generate values one at a
time using the yield keyword.
Example:
def
my_generator():
yield 1
yield 2
yield 3
for
value in my_generator():
print(value)
Output:
Copy
code
1
2
3
Q9.
What are metaclasses in Python?
Answer:
Metaclasses are classes of a class that define how a class behaves. A class is
an instance of a metaclass in Python.
Example:
class
Meta(type):
def __new__(cls, name, bases, dct):
dct['greet'] = lambda self: "Hello!"
return super().__new__(cls, name,
bases, dct)
class
MyClass(metaclass=Meta):
pass
obj
= MyClass()
print(obj.greet()) # Output: Hello!
Q10.
What is the difference between deepcopy and copy?
Answer:
- copy.copy():
Creates a shallow copy of an object (nested objects are not copied).
- copy.deepcopy():
Creates a deep copy of an object (nested objects are also copied).
Example:
import
copy
list1
= [[1, 2], [3, 4]]
shallow_copy
= copy.copy(list1)
deep_copy
= copy.deepcopy(list1)
list1[0][0]
= 0
print(shallow_copy) # Output: [[0, 2], [3, 4]]
print(deep_copy) # Output: [[1, 2], [3, 4]]
4. Scenario-Based Python Interview
Questions
Q11.
How would you optimize Python code for performance?
Answer:
- Use built-in libraries and functions.
- Implement efficient data structures
like deque or set.
- Utilize NumPy for numerical
computations.
- Leverage multi-threading or
multi-processing for parallel execution.
- Profile the code using cProfile or line_profiler.
Q12.
How would you handle errors in Python?
Answer:
Python uses try-except blocks to handle exceptions.
Example:
try:
x = 10 / 0
except
ZeroDivisionError as e:
print(f"Error: {e}")
finally:
print("Execution complete.")
5. Python Libraries and Frameworks
Q13.
What is Flask, and how does it differ from Django?
Answer:
- Flask:
A micro web framework for building lightweight applications.
- Django:
A full-stack web framework with built-in features like ORM and admin
panel.
Key
Differences:
|
Feature |
Flask |
Django |
|
Size |
Lightweight |
Heavyweight |
|
Flexibility |
High |
Less |
|
Built-In
ORM |
No |
Yes |
Q14.
What is NumPy, and why is it used?
Answer:
NumPy is a Python library for numerical computations, offering support for
multi-dimensional arrays, mathematical operations, and linear algebra.
Example:
import
numpy as np
arr
= np.array([1, 2, 3])
print(arr.mean()) # Output: 2.0
6. Python Coding Challenges
Q15.
Write a Python program to check if a string is a palindrome.
Answer:
def
is_palindrome(s):
return s == s[::-1]
print(is_palindrome("radar")) # Output: True
print(is_palindrome("python")) # Output: False
Q16.
Write a Python program to find the factorial of a number.
Answer:
def
factorial(n):
return 1 if n == 0 else n * factorial(n - 1)
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