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Short note, by Codesarray, , 2 min read

Reverse a string in Python with slicing: [::-1]

Slice a Python string with a step of minus one and you get it backwards, with no loop and no function. The same trick checks for a palindrome.

To reverse a string in Python, slice it with a step of minus one: word[::-1]. There is no loop and no function to call, just three characters after the name.

Reverse with [::-1]

word = "stressed"
print(word[::-1])
desserts

A slice has three parts, start:stop:step. Leaving start and stop empty means the whole string, and a step of -1 walks it backwards, one character at a time.

Check a palindrome

name = "level"
print(name[::-1])
print(name == name[::-1])
level
True

A palindrome reads the same both ways, so comparing a string to its reverse tells you whether it is one.

Things to know

  • Strings never change, so [::-1] returns a new string and the original stays as it was.
  • It works on any string, and on lists and tuples too.
  • Case and spaces count, so "Level" is not equal to its reverse.

This is a short note on Strings, lesson 4 of the Python beginner track.

This article goes with the video Reverse a string in Python. Watch it on YouTube.