10 Essential Python Interview Questions and Answers to Boost Your Prep

Whether you are applying for a Python web developer, crawler engineer, data analyst, or automation operations role, certain fundamental knowledge is essential. Below are ten basic Python interview questions with answers to help you prepare.

Question 1: How to modify the Python code so that it calls the show method of class A?

Answer: This question tests class inheritance; you can specify the class object using the __class__ attribute. The required code addition is shown below.

Question 2: How to modify the following Python code so that it runs?

Answer: This question examines method objects. To allow an instance to be called directly, implement the __call__ method as shown.

Question 3: What is the output of the following code?

Answer:

This question tests the use of __new__ and __init__. __new__ decides which object to return before creation (useful in singleton or factory patterns), while __init__ runs after the object is created.

Question 4: What does the following code output?

Answer:

This question examines list and dictionary comprehensions.

Question 5: What does the following code output?

Answer:

This question tests global vs. local variables. num is not a global variable, so each function gets its own copy. To modify the global num, you must declare it with the global keyword, as illustrated below.

Question 6: How to swap the values of two variables in a single line of code?

Answer:

Question 7: How to add code so that any undefined method call falls back to mydefault?

Answer:

This question tests Python's default method handling. When an undefined method is called, __getattr__ is invoked. By adding a *args parameter to mydefault, it can accept arbitrary arguments.

Question 8: In a package with modules mod1.py, mod2.py, mod3.py, how to ensure that from demopack import * imports only mod1 and mod3?

Answer: Add an __init__.py file to the package and include:

Question 9: Write a function that takes an integer n and returns another function that returns the product of n and its argument.

Answer:

Question 10: What is the hidden risk in the following Python 2 code?

Answer: Because str is an immutable object, each iteration creates a new str instance. As num grows, more string objects are created, leading to increased memory consumption.