# Python | List Inversions

• Last Updated : 23 Jan, 2020

Sometimes, while programming, we have a problem in which we might need to perform certain bitwise operations among list elements. This is an essential utility as we come across bitwise operations many times. Letâ€™s discuss certain ways in which this task can be performed.

Method #1 : Using `map() + lambda + "~" operator`
The above functions can be combined to perform this task. We can employ map() to accumulate the result of Inversion logic specified by the lambda function.

 `# Python3 code to demonstrate working of ` `# List Inversions ` `# Using map() + lambda + "~" operator ` ` `  `# initializing list ` `test_list ``=` `[``7``, ``8``, ``9``, ``1``, ``10``, ``7``] ` ` `  `# printing original list ` `print``(``"The original list is : "` `+` `str``(test_list)) ` ` `  `# List Inversions ` `# Using map() + lambda + "~" operator ` `res ``=` `list``(``map``(``lambda` `x: ~x, test_list))  ` ` `  `# printing result  ` `print``(``"The Bitwise Inversions of list elements are : "` `+` `str``(res)) `

Output :

```The original list is : [7, 8, 9, 1, 10, 7]
The Bitwise Inversions of list elements are : [-8, -9, -10, -2, -11, -8]
```

Method #2 : Using `map() + operator.invert`
This task can also be performed using this method. In this the task performed by lambda function in above method is performed using ior function for cumulative Inversion operation.

 `# Python 3 code to demonstrate working of ` `# List Inversions ` `# Using map() + operator.invert ` `from` `operator ``import` `invert ` ` `  `# initializing list ` `test_list ``=` `[``7``, ``8``, ``9``, ``1``, ``10``, ``7``] ` ` `  `# printing original list ` `print``(``"The original list is : "` `+` `str``(test_list)) ` ` `  `# List Inversions ` `# Using map() + operator.invert ` `res ``=` `list``(``map``(invert, test_list)) ` ` `  `# printing result  ` `print``(``"The Bitwise Inversions of list elements are : "` `+` `str``(res)) `

Output :

```The original list is : [7, 8, 9, 1, 10, 7]
The Bitwise Inversions of list elements are : [-8, -9, -10, -2, -11, -8]
```

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