Python Interview Questions and Answers

Last Updated : 14 Oct, 2025

Python is the most used language in top companies such as Intel, IBM, NASA, Pixar, Netflix, Facebook, JP Morgan Chase, Spotify and many more because of its simplicity and powerful libraries. To crack their Online Assessment and Interview Rounds as a Python developer, we need to master important Python Interview Questions.

1. Is Python a compiled language or an interpreted language?

Please remember one thing, whether a language is compiled or interpreted or both is not defined in the language standard. In other words, it is not a properly of a programming language. Different Python distributions (or implementations) choose to do different things (compile or interpret or both). However the most common implementations like CPython do both compile and interpret, but in different stages of its execution process.

  • Compilation: When you write Python code and run it, the source code (.py files) is first compiled into an intermediate form called bytecode (.pyc files). This bytecode is a lower-level representation of your code, but it is still not directly machine code. It’s something that the Python Virtual Machine (PVM) can understand and execute.
  • Interpretation: After Python code is compiled into bytecode, it is executed by the Python Virtual Machine (PVM), which is an interpreter. The PVM reads the bytecode and executes it line-by-line at runtime, which is why Python is considered an interpreted language in practice.

Some implementations, like PyPy, use Just-In-Time (JIT) compilation, where Python code is compiled into machine code at runtime for faster execution, blurring the lines between interpretation and compilation.

2. How can you concatenate two lists in Python?

We can concatenate two lists in Python using the +operator or the extend() method.

1. Using the + operator:

This creates a new list by joining two lists together.

Python 
a = [1, 2, 3]
b = [4, 5, 6]
res = a + b
print(res)

Output
[1, 2, 3, 4, 5, 6]

2. Using the extend() method:

This adds all the elements of the second list to the first list in-place.

Python 
a = [1, 2, 3]
b = [4, 5, 6]
a.extend(b)
print(a)

Output
[1, 2, 3, 4, 5, 6]

3. Difference between for loop and while loop in Python

  • For loop: Used when we know how many times to repeat, often with lists, tuples, sets, or dictionaries.
  • While loop: Used when we only have an end condition and don’t know exactly how many times it will repeat.
Python 
for i in range(5):
    print(i)

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

Output
0
1
2
3
4
0
1
2
3
4

To floor a number in Python, you can use the math.floor() function, which returns the largest integer less than or equal to the given number.

  • floor()method in Python returns the floor of x i.e., the largest integer not greater than x. 
  • Also, The method ceil(x) in Pythonreturns a ceiling value of x i.e., the smallest integer greater than or equal to x.
Python 
import math

n = 3.7
F_num = math.floor(n)

print(F_num)

Output
3

5. What is the difference between / and // in Python?

/ represents precise division (result is a floating point number) whereas // represents floor division (result is an integer). For Example:

Python 
print(5//2)
print(5/2)

Output
2
2.5

6. Is Indentation Required in Python?

Yes, indentation is required in Python. A Python interpreter can be informed that a group of statements belongs to a specific block of code by using Python indentation. Indentations make the code easy to read for developers in all programming languages but in Python, it is very important to indent the code in a specific order.