Python – Restrict Elements Frequency in List
Given a List, and elements frequency list, restrict frequency of elements in list from frequency list.
Input : test_list = [1, 4, 5, 4, 1, 4, 4, 5, 5, 6], restrct_dict = {4 : 3, 1 : 1, 6 : 1, 5 : 1}
Output : [1, 4, 5, 4, 4, 6]
Explanation : Limit of 1 is 1, any occurrence more than that is removed. Similar with all elements.
Input : test_list = [1, 4, 5, 4, 1, 4, 4, 5, 5, 6], restrct_dict = {4 : 2, 1 : 1, 6 : 1, 5 : 1}
Output : [1, 4, 5, 4, 6]
Explanation : Limit of 4 is 3, any occurrence more than that is removed. Similar with all elements.
Method : Using loop + defaultdict()
In this, we iterate for elements and and maintain lookup counter for each element using defaultdict(), if any element exceeds restrict dict, that element is not added then onwards.
Python3
# Python3 code to demonstrate working of# Restrict Elements Frequency in List# Using loop + defaultdict()from collections import defaultdict# initializing listtest_list = [1, 4, 5, 4, 1, 4, 4, 5, 5, 6]# printing original listprint("The original list is : " + str(test_list))# initializing restrct_dictrestrct_dict = {4 : 3, 1 : 1, 6 : 1, 5 : 2}res = []lookp = defaultdict(int)for ele in test_list: lookp[ele] += 1 # move to next ele if greater than restrct_dict count if lookp[ele] > restrct_dict[ele]: continue else: res.append(ele)# printing resultsprint("Filtered List : " + str(res)) |
The original list is : [1, 4, 5, 4, 1, 4, 4, 5, 5, 6] Filtered List : [1, 4, 5, 4, 4, 5, 6]
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