String slicing behavior in Python

Introduction

String slicing helps you get parts of a word or sentence easily, like cutting a piece from a cake.

You want to get the first few letters of a name.

You need to remove the last character from a word.

You want to reverse a string to check if it reads the same backwards.

You want to get every second letter from a sentence.

Syntax

Python

string[start:stop:step]

start is where slicing begins (included). If empty, starts from the beginning.

stop is where slicing ends (excluded). If empty, goes to the end.

step is how many characters to jump each time. Default is 1.

Examples

Gets letters from position 1 up to 3 (4 is excluded), so prints 'ell'.

Python

text = "hello"
print(text[1:4])

Gets letters from start up to position 2, prints 'wor'.

Python

text = "world"
print(text[:3])

Gets letters from position 2 to the end, prints 'thon'.

Python

text = "python"
print(text[2:])

Gets every second letter from start to end, prints 'ace'.

Python

text = "abcdef"
print(text[::2])

Sample Program

This program shows different ways to slice a string: from the start, middle, end, and reversed.

Python

word = "programming"

# Get first 4 letters
first_part = word[:4]

# Get letters from position 3 to 7
middle_part = word[3:8]

# Get last 3 letters
last_part = word[-3:]

# Reverse the word
reversed_word = word[::-1]

print(f"First 4 letters: {first_part}")
print(f"Letters 3 to 7: {middle_part}")
print(f"Last 3 letters: {last_part}")
print(f"Reversed word: {reversed_word}")

Important Notes

If start or stop is negative, counting starts from the end of the string.

If step is negative, slicing goes backwards.

Slicing never changes the original string; it creates a new one.

Summary

String slicing extracts parts of a string using start, stop, and step positions.

Start is included, stop is excluded in the slice.

You can use negative numbers to count from the end or reverse the string.