# Python | Sort tuple list on basis of difference of elements

Sometimes, while working with data, we can have a problem of sorting them. There are many types of basis on which sorting can be performed. But this article discusses sorting on basis of difference of both elements of pair. Let’s discuss certain ways in which this can be done.

**Method #1 : Using sorted() + lambda**

The combination of above functionalities can be used to solve this problem. In this, sorting is performed by

`sorted()`

and lambda function is fed as key to perform desired sorting.`# Python3 code to demonstrate working of` `# Sort tuple list on basis of difference of elements` `# using sorted() + lambda` ` ` `# initialize list ` `test_list ` `=` `[(` `1` `, ` `4` `), (` `6` `, ` `5` `), (` `8` `, ` `10` `)]` ` ` `# printing original list ` `print` `(` `"The original list : "` `+` `str` `(test_list))` ` ` `# Sort tuple list on basis of difference of elements` `# using sorted() + lambda` `res ` `=` `sorted` `(test_list, key ` `=` `lambda` `sub: ` `abs` `(sub[` `1` `] ` `-` `sub[` `0` `]))` ` ` `# printing result` `print` `(` `"List after sorting by difference : "` `+` `str` `(res))` |

**Output :**

The original list : [(1, 4), (6, 5), (8, 10)] List after sorting by difference : [(6, 5), (8, 10), (1, 4)]

**Method #2 : Using sort() + comparator + cmp()**

This is yet another way to perform this task. In this, we pass the

`sort()`

, a comparator function which performs the similar difference logic using `cmp()`

. Works only in Python2.`# Python code to demonstrate working of` `# Sort tuple list on basis of difference of elements` `# using sort() + comparator + cmp()` ` ` `# comparator function` `def` `diff_sort(ele1, ele2):` ` ` `return` `cmp` `(ele2[` `0` `] ` `-` `ele2[` `1` `], ele1[` `0` `] ` `-` `ele1[` `1` `])` ` ` `# initialize list ` `test_list ` `=` `[(` `1` `, ` `4` `), (` `6` `, ` `5` `), (` `8` `, ` `10` `)]` ` ` `# printing original list ` `print` `(` `"The original list : "` `+` `str` `(test_list))` ` ` `# Sort tuple list on basis of difference of elements` `# using sort() + comparator + cmp()` `test_list.sort(diff_sort)` ` ` `# printing result` `print` `(` `"List after sorting by difference : "` `+` `str` `(test_list))` |

**Output :**

The original list : [(1, 4), (6, 5), (8, 10)] List after sorting by difference : [(6, 5), (8, 10), (1, 4)]

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