input: Write a function to optimize the given Python code using best practices. The original function performs a linear search on an array to find the index of a specific element. If the element is found, it returns the index; otherwise, it returns -1.
  def optimize_linear_search(func):
      def linear_search(arr, x):
          for index, item in enumerate(arr):
              if item == x:
                  return index
          return -1
      return linear_search
  assert optimize_linear_search(linear_search)([1, 2, 3, 4], 3) == 2
  assert optimize_linear_search(linear_search)([1, 2, 3, 4], 5) == -1
  assert optimize_linear_search(linear_search)([], 3) == -1
  assert optimize_linear_search(linear_search)([3, 3, 3], 3) == 0
output: def linear_search(arr, x):
      for index, item in enumerate(arr):
          if item == x:
              return index
      return -1