Python | Print all common elements of two lists

Python Methods and Functions

Examples:

` Input: list1 = [1, 2, 3, 4, 5] list2 = [5, 6, 7, 8, 9] Output: {5} Explanation: The common elements of both the lists are 3 and 4 Input: list1 = [1, 2, 3, 4, 5] list2 = [6, 7, 8, 9] Output: No common elements Explanation: They do not have any elements in common in between them `

Method 1: Using Set & amp; property

Convert lists to sets, and then type set1 and set2 . set1 & amp; set2 returns a set of common elements, where set1 — it is list1, and set2 — this is list2.

Below is the implementation of the above approach in Python3:

 ` # Python program for finding common elements ` ` # in two lists ` ` def ` ` common_member (a, b): ` ` ` ` a_set ` ` = ` ` set ` ` (a) ` ` b_set ` ` = ` ` set ` ` (b) ` ` if ` ` (a_set & amp; b_set): ` ` ` ` print ` ` (a_set & amp; b_set) ` ` else ` `: ` ` print ` ` (` ` "No common elements" ` `) `     ` a ` ` = ` ` [` ` 1 ` `, ` ` 2 ` `, ` ` 3 ` `, ` ` 4 ` `, ` ` 5 ` `] ` ` b ` ` = ` ` [` ` 5 ` `, ` ` 6 ` `, ` ` 7 ` `, ` ` 8 ` `, ` ` 9 ` `] ` ` common_member (a, b) `   ` a ` ` = ` ` [` ` 1 ` `, ` ` 2 ` `, ` ` 3 ` `, ` ` 4 ` `, ` ` 5 ` `] ` ` b ` ` = ` ` [` ` 6 ` `, ` ` 7 ` `, ` ` 8 ` `, ` ` 9 ` `] ` ` common_m ember (a, b) `

Exit:

` {5} No common elements `

Method 1: Using the Set intersection property

Transform the list, to install by converting. Use the

` # Python program for finding common elements in `
` # both sets using the intersect function in `
` # sets `

` # function `

` def ` ` common_member (a, b): `

` a_set ` ` = ` ` set ` ` (a) `

` b_set ` = ` set ` ` (b) `

` # check length `

` if ` ` len ` ` ( a_set.intersection (b_set)) & gt; ` ` 0 ` `: `

` return ` ` (a_set.intersection (b_set)) `

` else ` `: `

` return ` ` (` ` "no common elements" ` ` ) `

` a ` ` = ` ` [` ` 1 ` `, ` ` 2 ` `, ` ` 3 ` `, ` ` 4 ` `, ` ` 5 ` `] `

` b = [ 5 , 6 , 7 , 8 , 9 ] `

` print (common_member (a, b))   a = [ 1 , 2 , 3 , 4 , 5 ] b = [ 6 , 7 , 8 , 9 ] print (common_member (a, b)) `

` `

Exit :

` {5} No common elements `