Python | Program to print duplicates from a list of integers
Given a list of integers with duplicate elements in it. The task to generate another list, which contains only the duplicate elements. In simple words, the new list should contain the elements which appear more than one.
Examples :
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Input : list = [10, 20, 30, 20, 20, 30, 40, 50, -20, 60, 60, -20, -20] Output : output_list = [20, 30, -20, 60] Input : list = [-1, 1, -1, 8] Output : output_list = [-1]
Method 1: Using the Brute Force approach
Below is the implementation :
Python3
# Python program to print# duplicates from a list# of integersdef Repeat(x): _size = len(x) repeated = [] for i in range(_size): k = i + 1 for j in range(k, _size): if x[i] == x[j] and x[i] not in repeated: repeated.append(x[i]) return repeated# Driver Codelist1 = [10, 20, 30, 20, 20, 30, 40, 50, -20, 60, 60, -20, -20]print (Repeat(list1)) # This code is contributed# by Sandeep_anand |
Output :
[20, 30, -20, 60]
Method 2: Using Counter() function from collection module
Python3
from collections import Counterl1 = [1,2,1,2,3,4,5,1,1,2,5,6,7,8,9,9]d = Counter(l1)print(d)new_list = list([item for item in d if d[item]>1])print(new_list) |
Output
Counter({1: 4, 2: 3, 5: 2, 9: 2, 3: 1, 4: 1, 6: 1, 7: 1, 8: 1})
[1, 2, 5, 9]
