Python built-in Method - reversed()

The reversed() function is a built-in Python method that returns a reverse iterator for a sequence. The sequence can be a list, a tuple, a string, or any other iterable object.

The syntax for the reversed() function is as follows:

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reversed(seq)
  • seq: The sequence to be reversed.

Here are some examples of how the reversed() function can be used:

>>> lst = [1, 2, 3, 4, 5]
>>> for i in reversed(lst):
...     print(i)
...
5
4
3
2
1

In this example, we use the reversed() function to get a reverse iterator for the lst list. We then use a for loop to iterate over the reversed sequence and print each value.

>>> s = "hello"
>>> for c in reversed(s):
...     print(c)
...
o
l
l
e
h

In this example, we use the reversed() function to get a reverse iterator for the s string. We then use a for loop to iterate over the reversed sequence and print each character.

>>> x = (1, 2, 3, 4, 5)
>>> y = reversed(x)
>>> print(list(y))
[5, 4, 3, 2, 1]

In this example, we use the reversed() function to get a reverse iterator for the x tuple. We then use the list() constructor to convert the reversed iterator to a list and print the result.

The reversed() function is a simple but useful built-in method in Python that provides a convenient way to iterate over a sequence in reverse order. It is often used in conjunction with for loops and list comprehensions to perform operations on a sequence in reverse order.