input: def optimize_linear_search(arr, x):
      """ Optimizes the provided linear search function using python best practices.
      >>> optimize_linear_search([10, 20, 80, 30, 60, 50, 110, 100, 130, 170], 110)
      6
      >>> optimize_linear_search([10, 20, 80, 30, 60, 50, 110, 100, 130, 170], 175)
      -1
      """
      for index, item in enumerate(arr):
          if item == x:
              return index
      return -1
output:     for index, item in enumerate(arr):
          if item == x:
              return index
      return -1