input: Write a function to suggest an improvement for the given Python code which finds the sum of elements in a list. The improved code should be more concise. If the input list is empty, the function should return 0.
  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
output: def sum_elements(lst):
      return sum(lst)