The reversed() method computes the reverse of a given sequence object and returns it in the form of a list.
Example
seq_string = 'Python'
# reverse of a string
print(list(reversed(seq_string)))
# Output: ['n', 'o', 'h', 't', 'y', 'P']
reversed() Syntax
The syntax of reversed() is:
reversed(sequence_object)
reversed() Parameter
The reversed() method takes a single parameter:
- sequence_object - an indexable object to be reversed (can be a tuple, string, list, range, etc.)
Note: Since we can't index objects such as a set and a dictionary, they are not considered sequence objects.
reversed() Return Value
The reversed() method returns:
- a reversed list of items present in a sequence object
Example 1: Python reversed() with Built-In Sequence Objects
seq_tuple = ('P', 'y', 't', 'h', 'o', 'n')
# reverse of a tuple object
print(list(reversed(seq_tuple)))
seq_range = range(5, 9)
# reverse of a range
print(list(reversed(seq_range)))
seq_list = [1, 2, 4, 3, 5]
# reverse of a list
print(list(reversed(seq_list)))
Output
['n', 'o', 'h', 't', 'y', 'P'] [8, 7, 6, 5] [5, 3, 4, 2, 1]
In the above example, we have used the reversed() method with objects like tuple, range and a list.
When using the reversed() method with these objects, we need to use the list() method to convert the output from the reversed() method to a list.
Example 2: reversed() with Custom Objects
class Vowels:
vowels = ['a', 'e', 'i', 'o', 'u']
def __reversed__(self):
return reversed(self.vowels)
v = Vowels()
# reverse a custom object v
print(list(reversed(v)))
Output
['u', 'o', 'i', 'e', 'a']
In the above example, we have used the reversed() method with a custom object v of the Vowels class.
Here, the method returns the reverse order of the sequence in the vowels list.
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