input: Write a function to suggest an improvement for the given Python code for finding the sum of elements of a list. The new function should use a more efficient approach, returning the sum in one line of code. Additionally, provide assert statements to test the function with expected results.
  
  assert sum_elements([1, 2, 3, 4, 5]) == 15
  assert sum_elements([-1, -2, -3, -4, -5]) == -15
  assert sum_elements([]) == 0
  assert sum_elements([10]) == 10
  assert sum_elements([0, 0, 0]) == 0
output: def sum_elements(lst):
      return sum(lst)