String Operations: Python Interview Questions and Answers

Introduction

Python string operations are a topic that frequently appears in technical interviews for Python developers. Being proficient in string manipulation can make you stand out during the interview process. In this blog post, we’ll cover some common interview questions related to Python string operations, along with their answers.

Question 1: How to Reverse a String?

Interviewer:

How can you reverse a string in Python?

Answer:

Python offers multiple ways to reverse a string. One of the simplest methods is using slicing.

string = "hello"
reversed_string = string[::-1]

You can also reverse a string using a loop:

string = "hello"
reversed_string = ''.join(reversed(string))

Question 2: How to Count the Occurrence of a Substring?

Interviewer:

Write a Python program to count the number of occurrences of a substring within a string.

Answer:

You can use the count() method to achieve this.

string = "hello world, hello universe"
substring = "hello"
count = string.count(substring)

Question 3: How to Convert a String to Uppercase?

Interviewer:

How can you convert a string to uppercase in Python?

Answer:

The upper() method can be used to convert all characters in a string to uppercase.

string = "hello"
uppercase_string = string.upper()

Question 4: How to Check if a String Starts With a Specific Substring?

Interviewer:

How can you check if a string starts with a specific substring?

Answer:

You can use the startswith() method to check if a string starts with a specific substring.

string = "hello"
result = string.startswith("he")

Question 5: How to Split a String Into a List?

Interviewer:

How would you split a string into a list of words?

Answer:

The split() method can be used to split a string into a list based on a delimiter.

string = "hello world"
list_of_words = string.split(" ")

Question 6: How to Join a List of Strings?

Interviewer:

What is the way to join a list of strings into a single string?

Answer:

You can use the join() method to concatenate a list of strings into a single string.

list_of_words = ["hello", "world"]
string = " ".join(list_of_words)

Question 7: How to Replace a Substring?

Interviewer:

How would you replace occurrences of a substring within a string?

Answer:

The replace() method can be used to replace all occurrences of a substring.

string = "hello world"
new_string = string.replace("world", "universe")

Question 8: How to Remove Leading and Trailing Whitespaces?

Interviewer:

How can you remove leading and trailing whitespaces from a string?

Answer:

The strip() method can be used to remove leading and trailing whitespaces.

string = "   hello world  "
stripped_string = string.strip()

Conclusion

Understanding Python string operations is crucial for tackling string manipulation questions in technical interviews. By practicing these questions, you’ll be well-prepared to demonstrate your Python skills in your next job interview.