Python continues to be the most in-demand programming language in 2026, leading innovation in AI, ML, Cloud Computing, Automation, Data Science, Cybersecurity, IoT, Web Development, and DevOps. Recruiters are actively hiring Python professionals freshers, mid-level developers, and senior engineers who can demonstrate not just theoretical knowledge but also strong hands-on reasoning.
This guide covers the latest and most Latest Python interview questions you must master in 2026. Whether you’re preparing for a Python Developer role, Data Engineering job, or Automation Testing position, this resource will help you stand out. If you’re also pursuing Python Certification Online, these interview questions will strengthen your concepts and boost your confidence for real-world job interviews.
1. Why is Python still so popular in 2026?
Python has maintained its #1 position in 2026 due to:
- Readable, beginner-friendly syntax
- Huge ecosystem for AI, ML, web, data, cloud, and analytics
- Cross-platform support
- Powerful frameworks (Django, Flask, FastAPI, Pandas, NumPy, TensorFlow)
- Rich standard library
- Strong community support
- Integration with cloud providers (AWS Lambda, GCP Functions, Azure Functions)
Companies rely on Python not just for rapid development but also for scalability, automation, and data-heavy applications. This is why Python Latest interview topics are becoming deeper and more practical each year.
2. What’s new in Python 3.12 and 3.13? (2026 update)
Python 3.12 and 3.13 delivered major improvements:
Faster CPython Execution
Python 3.12 introduced up to 40% speed improvements, while 3.13 enhances startup performance, garbage collection, and optimization.
Improved Error Messages
Python now provides smart error hints critical for debugging test automation and backend systems.
Removal of Deprecated Modules
Outdated libraries were removed to streamline performance.
Enhanced asyncio
Async programming now matches Node.js-level performance, making Python preferred for microservices.
Experimental “No-GIL” Python
Python 3.13 includes a nogil test build for true Latest multithreading one of the hottest interview topics for 2026.
3. What is PEP 8 and why is it important?
PEP 8 is the official Python style guide that defines rules for:
- Indentation
- Variable naming
- Spacing
- Code layout
- Commenting
- Import structure
- Best practices for readability
Following PEP 8 helps maintain clean, readable, and professional code something hiring managers expect from every Python developer.
4. Explain Latest key differences between List, Tuple, Set, and Dictionary.
| Type | Ordered | Mutable | Allows Duplicates | Use Case |
|---|---|---|---|---|
| List | Yes | Yes | Yes | Dynamic collections |
| Tuple | Yes | No | Yes | Immutable data like config |
| Set | No | Yes | No | Unique values, membership checks |
| Dictionary | Yes (Py3.7+) | Yes | Keys unique | Key–value mapping |
Understanding these differences is fundamental for optimizing algorithms and memory usage.
5. What is the difference between “==” and “is”?
- == compares values
- is compares memory identity
Example:
a = [1,2] b = [1,2] print(a == b) # True print(a is b) # False
6. What are Python decorators? Give an example.
Decorators allow you to modify Latest function behavior without changing code.
Example:
def log(func):
def wrapper(*args, **kwargs):
print("Function executed")
return func(*args, **kwargs)
return wrapper
@log
def greet():
print("Hello!")
Used in:
- Django middleware
- FastAPI routes
- Logging
- Authorization
- Caching
7. What is the GIL (Global Interpreter Lock)? Is Python removing it in 2026?
GIL Definition
A mutex that allows only one thread to execute Python bytecode at a time.

Problem
Limits true multithreading for CPU-heavy tasks.
2026 Update
- Python 3.13 includes an Latest experimental No-GIL build
- Significant progress in PEP 703
- Expected to roll out in stable versions soon
This is one of the hottest Python interview topics for 2026.
8. Explain shallow copy vs deep copy.
import copy original = [[1,2],[3,4]] shallow = copy.copy(original) deep = copy.deepcopy(original)
- Shallow copy copies references
- Deep copy copies entire objects
Useful for understanding memory management in large data structures.
9. What are lambda functions?
Small, anonymous functions created using lambda.
square = lambda x: x * x
Used heavily in:
- Sorting
- Filtering
- Machine Learning pipelines
- Map/Reduce
10. What are list comprehensions? Why are they faster?
Latest List comprehensions provide a short and optimized way to create lists.
result = [x*x for x in range(10)]
They are faster because:
- They run in C-level loops
- Reduce overhead of Latest Python bytecode
- Improve readability
11. What is *args and kwargs?
Used to pass variable arguments:
def func(*args, **kwargs):
print(args)
print(kwargs)
*args→ positional arguments**kwargs→ keyword arguments
12. What are generators and why are they useful?
Generators return sequence values using yield no need to store everything in memory.
def counter():
for i in range(5):
yield i
Benefits:
- Very memory efficient
- Used in Latest streaming, data pipelines
- Essential for large-scale ML/ETL systems
13. Explain Python’s Memory Management Model.
Python manages memory using:
- Private Heap (for objects)
- Reference Counting
- Garbage Collector
- Generational GC Algorithm
Python abstracts memory details, improving developer productivity.
14. What is a module vs a package?
- Module = single Python file
- Package = folder with multiple modules
Example:
mypackage/
__init__.py
module1.py
module2.py
15. What is virtualenv and why is it used?
It creates isolated Python environments, preventing version conflicts.
Tools:
- virtualenv
- pipenv
- conda
- poetry
Essential for multi-project development.
16. Explain exception handling with an example.
try:
x = 10 / 0
except ZeroDivisionError:
print("Cannot divide by zero")
Common exceptions:
- KeyError
- TypeError
- FileNotFoundError
- IndexError
17. What is asynchronous programming in Python? Why is it trending in 2026?
Async programming allows concurrent execution of tasks using asyncio.
import asyncio
async def run():
print("Async function")
asyncio.run(run())
Why trending?
- API-first development
- FastAPI adoption
- Microservices
- High-performance backend systems
18. What is structural pattern matching? (PEP 634)
Pattern matching, introduced in Python 3.10, functions like a powerful switch-case.
def check(x):
match x:
case 0:
return "Zero"
case [a, b]:
return f"List with two items: {a}, {b}"
Used in:
- Data parsing
- DSL interpreters
- Routing logic
19. Difference between multithreading and multiprocessing?
Multithreading
- Good for I/O tasks
- Limited by GIL
Multiprocessing
- Bypasses GIL
- Best for CPU-bound tasks
- Spawns separate processes
Used in:
- ML training
- Image processing
- Large dataset transformations
20. Explain the use of __init__, __str__, and __repr__.
class Student:
def __init__(self, name):
self.name = name
def __str__(self):
return f"Name: {self.name}"
def __repr__(self):
return f"Student(name={self.name})"
__init__→ constructor__str__→ human-readable text__repr__→ debugging text
21. What are dataclasses? Why are they useful in 2026?
Introduced in Python 3.7, dataclasses automatically generate:
__init____repr____eq__
Example:
from dataclasses import dataclass
@dataclass
class User:
name: str
age: int
Used heavily in:
- FastAPI models
- ML configs
- ETL pipelines
22. Explain the difference between Django and FastAPI.
Django
- Full-featured web framework
- Great for dashboards, admin, e-commerce
FastAPI
- Extremely fast, async-first
- Ideal for microservices, ML model serving
FastAPI is a must-know for 2026 backend interviews.
23. What is monkey patching?
Changing a class or function at runtime.
import math math.pi = 3
Used in:
- Testing
- Hotfixing
- Dynamic behavior injection
24. How do you handle memory-intensive tasks in Python?
- Use NumPy arrays
- Use generators
- Use batch processing
- Use multiprocessing
- Offload to GPU using PyTorch/TF
25. Explain Python’s OOP features.
Python supports:
- Encapsulation
- Inheritance
- Abstraction
- Polymorphism
- Multiple inheritance
- Method overriding
26. What is a closure?
A function that captures variables from its outer scope.
def make_multiplier(n):
def inner(x):
return x * n
return inner
Closures power decorators, callbacks, and function factories.
27. What are type hints? (PEP 484)
def add(a: int, b: int) -> int:
return a + b
Used for:
- Static checking
- Documentation
- IDE autocompletion
- Clean ML and API code
Type hints are mandatory in most 2026 Python jobs.
28. What is the difference between synchronous and asynchronous code?
| Synchronous | Asynchronous |
|---|---|
| Blocking | Non-blocking |
| One task at a time | Multiple tasks concurrently |
| Slower APIs | Faster APIs |
| Used for CPU tasks | Used for network/IO tasks |
29. Explain Python memory leaks and how to avoid them.
Causes:
- Circular references
- Unclosed file/network connections
- Large global variables
- Overuse of caches
Prevention:
- Use
weakref - Context managers (
with) - Monitor with tracemalloc
30. What is PySpark and why is it trending?
PySpark is Python’s API for Apache Spark.
Used for:
- Big Data processing
- ETL pipelines
- Distributed ML
Companies using huge datasets expect Python developers to know PySpark.
31. What are Python’s context managers and how do they work?
Latest Context managers allow you to allocate and release resources automatically, using the with statement.
They implement two methods:
__enter__()__exit__()
Example:
with open("data.txt", "r") as file:
content = file.read()
Benefits:
- Auto-closes files
- Prevents memory leaks
- Used in database Latest connections, locks, transactions
32. What is the difference between @staticmethod and @classmethod?
@staticmethod
- No access to class or instance
- Behaves like a plain function inside a class
@classmethod
- Receives class (
cls) as the first argument
Example:
class Demo:
@staticmethod
def add(a, b):
return a+b
@classmethod
def info(cls):
return "Class method"
33. What is memoryview in Python?
memoryview allows you to access memory buffers without copying data.
data = bytearray('Python', 'utf-8')
mv = memoryview(data)
Useful for:
- Large binary files
- Performance-sensitive operations
- Image processing
34. What is the purpose of the “yield from” keyword?
Introduced in Latest Python 3.3, yield Latest from delegates part of a generator to another generator.
def gen1():
yield from range(3)
It simplifies:
- Nested generators
- Coroutine delegation
- Async tasks
35. What is monkey patching in Python?
Monkey patching allows modification of classes or modules at runtime.
import math
math.pi = 3
Used in:
- Testing
- Hotfixes
- Mocking APIs
36. What are Python’s built-in data types?
- Numeric →
int,float,complex - Sequence →
list,tuple,range - Mapping →
dict - Set →
set,frozenset - Boolean →
True,False - Text →
str - Binary →
bytes,bytearray,memoryview
37. What is the difference between Process Pool and Thread Pool?
ThreadPoolExecutor
- Uses threads
- Limited by GIL
- Suitable for I/O tasks
ProcessPoolExecutor
- Uses multiple processes
- Bypasses GIL
- Suitable for CPU-heavy tasks
Example:
from concurrent.futures import ThreadPoolExecutor, ProcessPoolExecutor38. What is the purpose of functools.lru_cache()?
It caches function results to improve performance.
from functools import lru_cache
@lru_cache(maxsize=128)
def calc(n):
return n*n
Benefits:
- Fast computation
- Avoids repeated expensive operations
- Used in ML, recursion, and API caching
39. Explain difference between JSON, Pickle, and YAML in Python.
| Format | Readability | Safe | Use Case |
|---|---|---|---|
| JSON | Human readable | Safe | API, config |
| Pickle | Binary, Python-specific | Not secure | Local serialization |
| YAML | Very readable | Safe | DevOps configs (Kubernetes, Ansible) |
40. What is the difference between copy.copy() and copy.deepcopy()?
copy()
- Creates shallow copy
- References nested objects
deepcopy()
- Creates full independent copy
- No shared references
41. What is a metaclass in Python?
A meta class defines how Latest classes themselves are created
Default metaclass: type
Example:
class Meta(type):
def __new__(cls, name, bases, attrs):
return super().__new__(cls, name, bases, attrs)
Used for:
- Framework design
- ORM systems
- Enforcing coding rules
42. What is the difference between slots and normal class attributes?
_slots__ restricts attribute creation to a fixed set, saving memory
class User:
__slots__ = ['name', 'age']
Benefits:
- Less memory usage
- Faster attribute access
43. What is a frozen dataclass?
A dataclass that behaves like a tuple (immutable).
from dataclasses import dataclass
@dataclass(frozen=True)
class Point:
x: int
y: int
Prevents modification.
44. What are Python descriptors?
Descriptors manage attribute access using:
__get____set____delete__
Example:
class Descriptor:
def __get__(self, obj, objtype=None):
return "Value"
Used in:
- Properties
- ORM frameworks
- Validation logic
45. Explain garbage collection in Python.
Python uses:
- Reference Counting
- Generational Garbage Collector
- Cycle Detection
Latest Cycle detection removes circular references.
You can manually trigger GC:
import gc gc.collect()
46. What is the difference between range() and enumerate()?
range()
- Generates a sequence of numbers
enumerate()
- Returns index + element
for i, value in enumerate(['a','b','c']):
print(i, value)
47. What is the use of zip() in Python?
zip() combines multiple iterables into tuples
names = ["A", "B"]
scores = [90, 85]
for x in zip(names, scores):
print(x)
48. What is duck typing in Python?
Python does not check types; it checks behavior
“If it walks like a Latest duck and quacks like a duck, it’s a duck.”
Example:
class Duck:
def quack(self):
print("Quack")
class Person:
def quack(self):
print("I can quack too")
49. What is hashing in Python?
Hashing converts objects into integer values.
Used in:
- Dictionary keys
- Set membership checks
Example:
hash("Python")
Immutable types are hashable; mutable types are not.
50. What is the walrus operator (:=) in Python?
Introduced in Latest Python 3.8, it assigns and returns a value in one expression.
Example:
if (n := len([1,2,3])) > 2:
print(n)
Useful for:
- Shorter loops
- Validations
- Cleaner logic
Conclusion
Python remains the most powerful and versatile programming language in 2026, and employers now expect candidates to understand not just Latest basic syntax but also deeper concepts like async programming, the GIL, data classes, decorators, memory management, and modern frameworks such as FastAPI. If you’re learning Python Programming Online, mastering these advanced topics will give you a strong competitive Latest edge and prepare you for real-world development roles.
Mastering these interview questions will help you:
- Perform confidently in technical rounds
- Solve coding challenges with ease
- Impress interviewers with Latest practical insights
- Secure high-paying Python roles

























