Python Interview

Top Python String Methods You Must Know for Interviews

By JobQNA Team • Updated: Jan 10, 2025

Strings are one of the most commonly used data types in Python. Whether you are a beginner or an experienced developer, you will face string manipulation questions in almost every coding interview. In this guide, we will explore the most important string methods with practical examples.

1. How to Reverse a String in Python?

Unlike other languages, Python strings don't have a built-in reverse() method. However, the most Pythonic way to reverse a string is using slicing.

                # Method 1: Using Slicing

                text = "JobQNA"

                reversed_text = text[::-1]

                print(reversed_text)  # Output: ANQboJ

You can also use the reversed() function combined with join() for a more readable approach, although slicing is faster.

2. Checking for Palindromes

A palindrome is a word that reads the same backward as forward (e.g., "madam"). This is a classic interview question.

                def is_palindrome(s):

                    s = s.lower()  # Case insensitive

                    return s == s[::-1]

                print(is_palindrome("Racecar")) # Output: True

3. Splitting and Joining Strings

Data often comes in CSV format or raw text. You need split() to break it down and join() to combine it back.

                sentence = "Python,Java,C++,NodeJS"

                languages = sentence.split(",")

                print(languages) 

                # Output: ['Python', 'Java', 'C++', 'NodeJS']

                new_sentence = " | ".join(languages)

                print(new_sentence)

                # Output: Python | Java | C++ | NodeJS

4. Finding Substrings

Never use a loop to find a word in a string. Use the in keyword or find() method.

find() returns the index of the first occurrence.
It returns -1 if the value is not found.

                text = "Welcome to JobQNA Docs"

                index = text.find("Docs")

                print(index) # Output: 11

Pro Tip: Want a quick reference for all string methods? Check out our Python Cheat Sheet.

Conclusion

Mastering these string operations will give you a solid foundation for solving algorithmic problems on LeetCode or HackerRank. Practice these examples, and you'll be ready for your next technical interview.