input: Write a function to optimize the provided Python code using best practices. The original function performs a linear search on an array to find the index of a specified element. If the element is found, it returns the index; otherwise, it returns -1.
  
  def linear_search(arr, x):
      for index, item in enumerate(arr):
          if item == x:
              return index
      return -1
  assert linear_search([1, 2, 3, 4, 5], 3)==2
  assert linear_search([1, 2, 3, 4, 5], 6)==-1
  assert linear_search([], 3)==-1
  assert linear_search([1, 2, 3, 4, 5], 1)==0
output: def linear_search(arr, x):
      try:
          return arr.index(x)
      except ValueError:
          return -1