Python | Delete elements with frequency atmost K
There are many methods that can be employed to perform the deletion in the list. Be it remove function, pop function and many other functions. But most of the times, we usually don’t deal with the simple deletion, but with certain constraints. This article discusses certain ways in which we can delete only those elements which occurs less than K times.
Method #1 : Using list comprehension + count()
The idea applied here is to construct a new list using list comprehension and insert only those elements which occur more than K times. The count operation is done with the help of count function.
# Python3 code to demonstrate # remove elements less than and equal K # using list comprehension + count() # initializing list test_list = [1, 4, 3, 2, 3, 3, 2, 2, 2, 1] # printing original list print("The original list : " + str(test_list)) # initializing K K = 2 # using list comprehension + count() # remove elements less than K res = [ i for i in test_list if test_list.count(i) > K] # print result print("The list removing elements less than and equal K : " + str(res)) |
chevron_right
filter_none
Output :
The original list : [1, 4, 3, 2, 3, 3, 2, 2, 2, 1] The list removing elements less than and equal K : [3, 2, 3, 3, 2, 2, 2]
Method #2 : Using Counter() + list comprehension
This problem can be efficiently solved using the Counter function that precomputes the count of each elements in list so that the decision to keep or reject a particular element takes lesser time.
# Python3 code to demonstrate # remove elements less than and equal K # using Counter() + list comprehension from collections import Counter # initializing list test_list = [1, 4, 3, 2, 3, 3, 2, 2, 2, 1] # printing original list print("The original list : " + str(test_list)) # initializing K K = 2 # using Counter() + list comprehension # remove elements less than K freq = Counter(test_list) res = [ele for ele in test_list if freq[ele] > K] # print result print("The list removing elements less than and equal K : " + str(res)) |
chevron_right
filter_none
Output :
The original list : [1, 4, 3, 2, 3, 3, 2, 2, 2, 1] The list removing elements less than and equal K : [3, 2, 3, 3, 2, 2, 2]
Recommended Posts:
- Python | List frequency of elements
- Python | Sort list elements by frequency
- Python | Find sum of frequency of given elements in the list
- Python | Delete elements in range
- Python | Group list elements based on frequency
- Python | Frequency of substring in given string
- Python | Frequency of each character in String
- Python | Finding frequency in list of tuples
- Find frequency of each word in a string in Python
- Python | Element with largest frequency in list
- numpy.delete() in Python
- Python | Count all prefixes in given string with greatest frequency
- Python | Sort given list by frequency and remove duplicates
- Python | Pandas TimedeltaIndex.delete
- Python | Pandas Index.delete()
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.
