input: Write a function to improve the provided Python code for finding the sum of elements of a list. The improved function should use a more efficient method to calculate the sum and return it.
  assert sum_elements([1, 2, 3, 4, 5]) == 15
  assert sum_elements([0, -1, 1]) == 0
  assert sum_elements([]) == 0
  assert sum_elements([10]) == 10
output: def sum_elements(lst):
      return sum(lst)