God, who would have thought that the remaining identical numbers when calculating the average give an additional 0.7750000000000057 .............AAAAAAAA mathematics what's wrong with you

This is no one-liner for beginners to understand better. And, it doesn't use more space by creating extra variable. Prolly, the best code for anyone(amateur or pro).

def average(array):
    distinct_heights = set(array)
    return (sum(distinct_heights)/len(distinct_heights))

if __name__ == '__main__':
    n = int(input())
    arr = list(map(int, input().split()))
    result = average(arr)
    print(result)

• def average(array):
  • set_array = set(array)
  • average_count = sum(set_array)/len(set_array)
  • return f'%.3f' % average_count
• • if name == 'main':
  • n = int(input())
  • arr = list(map(int, input().split()))
  • result = average(arr)
  • print(result)