Python String Interview Questions (Top 50+)

String-related questions are very common in Python interviews. They test your understanding of string manipulation, logic building, and problem-solving skills.

In this guide, we cover the most frequently asked Python string interview questions with clear explanations and code examples.

1. Basic String Questions

Q1. What is a string in Python?

A string is a sequence of characters enclosed in quotes.

Q2. Are strings mutable?

No, strings are immutable in Python.

Q3. How to find length of a string?

              
Python

          Length of string
        
s = "hello"
print(len(s))

Q4. How to convert string to uppercase?

              
Python

          Uppercase
        
print("hello".upper())

2. Intermediate String Questions

Q5. Reverse a string

              
Python

          Reverse string
        
s = "hello"
print(s[::-1])

Q6. Check palindrome

              
Python

          Palindrome
        
s = input()
print("Palindrome" if s == s[::-1] else "Not")

Q7. Count vowels

              
Python

          Count vowels
        
s = input()
print(sum(1 for c in s if c.lower() in 'aeiou'))

Q8. Remove spaces

              
Python

          Remove spaces
        
s = input()
print(s.replace(" ", ""))

3. Advanced String Questions

Q9. Find first non-repeating character

              
            
Python

          First unique char
        
s = input()
for c in s:
    if s.count(c) == 1:
        print(c)
        break

Q10. Check anagram

              
Python

          Anagram
        
s1 = input()
s2 = input()
print(sorted(s1) == sorted(s2))

Q11. Longest substring without repeating characters

              
            
Python

          Longest substring
        
s = input()
char_set = set()
l = 0
max_len = 0

for r in range(len(s)):
    while s[r] in char_set:
        char_set.remove(s[l])
        l += 1
    char_set.add(s[r])
    max_len = max(max_len, r-l+1)

print(max_len)

4. Coding Challenges

1. Count words in a string.

2. Remove duplicates from string.

3. Capitalize first letter of each word.

4. Find frequency of characters.

5. Check if string contains only digits.

5. Interview Tips

1. Practice string problems regularly.

2. Learn built-in functions like split(), join().

3. Understand time complexity.

4. Write clean and readable code.

Conclusion

Python string questions are essential for coding interviews. Mastering these problems will improve your logic-building and problem-solving skills.

Practice consistently and explore advanced problems to excel in interviews.