input: Write a function to create a search engine in Python that performs a linear search through a given array. If the item is found, return its position; if not, return -1.
  assert linearSearch('mall')==3
  assert linearSearch('bookstore')==2
  assert linearSearch('park')==-1
  assert linearSearch('school')==0
  assert linearSearch('theatre')==4
output: def linearSearch(item):
      places = ['school', 'bookstore', 'mall', 'park', 'theatre']
      for i in range(len(places)):
          if places[i] == item:
              return i
      return -1