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Python – How to Check if two lists are reverse equal
• Last Updated : 03 Jul, 2020

Sometimes, while working with Python lists, we can have a problem in which we need to check if two lists are reverse of each other. This kind of problem can have application in many domains such as day-day programming and school programming. Let’s discuss certain ways in which this task can be performed.

Input : test_list1 = [5, 6, 7], test_list2 = [7, 6, 5]
Output : True

Input : test_list1 = [5, 6], test_list2 = [7, 6]
Output : False

Method #1 : Using `reversed() and "==" operator`
The combination of above functions can be used to solve this problem. In this, we perform the task of reversing using reversed() and testing for equality using “==” operator.

 `# Python3 code to demonstrate working of ``# Check if two lists are reverse equal``# Using reversed() + == operator`` ` `# initializing lists``test_list1 ``=` `[``5``, ``6``, ``7``, ``8``]``test_list2 ``=` `[``8``, ``7``, ``6``, ``5``]`` ` `# printing original lists``print``(``"The original list 1 : "` `+` `str``(test_list1))``print``(``"The original list 2 : "` `+` `str``(test_list2))`` ` `# Check if two lists are reverse equal``# Using reversed() + == operator``res ``=` `test_list1 ``=``=` `list``(``reversed``(test_list2))`` ` `# printing result ``print``(``"Are both list reverse of each other ? : "` `+` `str``(res))`
Output :

```The original list 1 : [5, 6, 7, 8]
The original list 2 : [8, 7, 6, 5]
Are both list reverse of each other ? : True
```

Method #2 : Using list slicing + “==” operator
This is yet another way to solve this problem. In this, we perform the task of list reversing using slice technique.

 `# Python3 code to demonstrate working of ``# Check if two lists are reverse equal``# Using list slicing + "==" operator`` ` `# initializing lists``test_list1 ``=` `[``5``, ``6``, ``7``, ``8``]``test_list2 ``=` `[``8``, ``7``, ``6``, ``5``]`` ` `# printing original lists``print``(``"The original list 1 : "` `+` `str``(test_list1))``print``(``"The original list 2 : "` `+` `str``(test_list2))`` ` `# Check if two lists are reverse equal``# Using list slicing + "==" operator``res ``=` `test_list1 ``=``=` `test_list2[::``-``1``]`` ` `# printing result ``print``(``"Are both list reverse of each other ? : "` `+` `str``(res))`
Output :
```The original list 1 : [5, 6, 7, 8]
The original list 2 : [8, 7, 6, 5]
Are both list reverse of each other ? : True
```

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