How to Reverse a List in Python Without Modifying the Original List?

Method Chaining for List Reversal

When working with lists, it's often desirable to create a reversed copy without explicitly using a separate statement. However, the built-in list.reverse() method returns None and modifies the list in-place.

The Issue

Consider the following code:

k = ['F', ' ', 'B', 'F']

def solution(formation):
    return (formation.index(bCamel) > (len(formation) - 1 - (formation.reverse()).index(fCamel)))

solution(k)

This code attempts to compare the indices of two characters (bCamel and fCamel) in a list that has been reversed. However, it raises an AttributeError because list.reverse() returns None, leaving (formation.reverse()) as None.

Solution: Using Slicing

Instead of relying on list.reverse(), you can use slicing to obtain a reversed list:

reversed_formation = formation[::-1]

The syntax [::-1] reverses the list without modifying it in-place. You can then use reversed_formation as needed:

def solution(formation):
    reversed_formation = formation[::-1]
    return (formation.index(bCamel) > (len(formation) - 1 - reversed_formation.index(fCamel)))

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