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1. Reverse a String2. Check Palindrome String3. Count Vowels in String4. Count Consonants in String5. Count Digits in String6. Remove Special Characters7. Remove Whitespace8. Find Substring9. Replace Substring10. Character Frequency11. Capitalize First Letter of Each Word12. Convert String to Title Case13. Sort String Characters14. Find Longest Word15. Find Shortest Word16. String Compression17. String Rotation18. Anagram Check19. Split and Join Strings20. Count Words in String21. Extract Numbers from String22. Validate Email Using Regex23. Validate Phone Number Using Regex24. Check Pangram25. Convert snake_case to camelCase

Find Substring in Python

Check if a substring exists within a string and find its index.

BeginnerString ProgramsExample 8 of 25
find-substring.py
1# Program to find substring in a string
2

3text = input("Enter main string: ")
4sub = input("Enter substring: ")
5

6index = text.find(sub)
7

8if index != -1:
9    print(f"Substring found at index {index}")
10else:
11    print("Substring not found")

Output

Enter main string: hello world
Enter substring: world
Substring found at index 6

What's going on

We use .find() which returns the starting index of the substring or -1 if not found.

After this program

If the idea is still fuzzy, read Day 4: Strings and String Methods in the Python course. For a short check, try the Python quiz (300 questions). Stay with all 25 string programs, or see every topic on Python exercises.

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