Python Practice › List Programs › Program 36
Numbers that appear exactly once
Write a Python program to get the numbers that appear exactly once in a list.
Input
[1, 2, 2, 3, 4, 4, 5]
Output
[1, 3, 5] [1, 2, 3, 4, 5]
Approach
- Count with
Counterand keep counts of 1.
Solution
from collections import Counter numbers = [1, 2, 2, 3, 4, 4, 5]counts = Counter(numbers)print([n for n in numbers if counts[n] == 1])print(list(dict.fromkeys(numbers)))Output
[1, 3, 5] [1, 2, 3, 4, 5]
Line by line
Line 5
Values that occur only once.
Line 6
Every distinct value (duplicates removed), for comparison.
Learn the concept
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