There are different ways to reverse a string in Python.
The usual way to reverse a string is to use slicing with a negative
>>> string = "hello world" >>> string[::-1] 'dlrow olleh'
Breaking it down,
string[:] means: "take the string from beginning to end",
string[::-1] means that the string should be taken one step at a time,
-1 to the index after each step.
The final result is that the string gets reversed.
If you don't understand precisely what's going on, don't worry too much about
it. Just put
[::-1] after your string (or list, or tuple) to reverse it.
There is a built-in function named
reversed that can give you an iterator
over the string that runs in reverse. For example:
>>> string = "abc" >>> for letter in reversed(string): ... print(letter) ... c b a
However you cannot print this iterator directly, or you will see the
>>> print(reversed("abc")) <reversed object at 0x7f8222e12210>
You can write your own function to reverse a string:
def reverse(string): result = "" index = len(string) - 1 while index >= 0: result += string[index] index -= 1 return result print(reverse("hello"))
Running the code correctly prints