 # Python | Sort this list by frequency and remove duplicates

Method # 1: Using count () + set () + sorted ()

The sort function can be used to sort items as desired, the frequency can be calculated using counting functions, and the removal of duplicates can be handled with the install function.

 ` # Python3 demo code ` ` # sorting and removing duplicates ` ` # Using sorted () + set () + count () `   ` # initializing list ` ` test_list ` ` = ` ` [` ` 5 ` `, ` ` 6 ` `, ` ` 2 ` `, 5 , 3 , 3 , 6 , 5 , 5 , 6 , 5 ] ````   # print original list print ( "The original list:" + str (test_list))   # using sorted () + set () + count () # sorting and removing duplicates res = sorted ( set (test_list), key = lambda ele: test_list.count (ele))   # print result print ( "The list after sorting and removal:" + str (res)) ```

Exit:

` The original list: [5, 6, 2, 5, 3, 3, 6, 5, 5, 6, 5] The list after sorting and removal: [2, 3, 6, 5] `

Method # 2: Using ` Counter.most_common () ` + List Comprehension

If there is a specific use case with By frequency descending ordering, you can also use the most common Counter library function to get the frequency part.

 ` # Python3 demo code ` ` # sort and remove duplicates ` ` # Using Counter.most_common () + list comprehension ` ` from ` ` collections ` ` import ` ` Counter ````   # initializing list test_list = [ 5 , 6 , 2 ,  5 , 3 , 3 , 6 , 5 , 5 , 6 , 5 ]   # print the original list print ( "The original list:" + str (test_list))   # using Counter.most_common () + comprehension list # sort and remove duplicate ov res = [key for key, value in Counter (test_list) .most_common ()]   # print result print ( "The list after sorting and removal: " + str (res)) ```

Output:

` The original list: [5, 6 , 2, 5, 3, 3, 6, 5, 5, 6, 5] The list after sorting and removal: [5, 6, 3, 2] `