input: Write a function to create a search engine in Python to quickly search through a given array. The function should perform a linear search and return the position of the search item if found, otherwise return -1. The array is defined as ['school', 'hospital', 'bookstore', 'mall', 'theatre'].
  def linearSearch(search_item):
      array = ['school', 'hospital', 'bookstore', 'mall', 'theatre']
      for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1
  
  assert linearSearch('hospital')==1
  assert linearSearch('mall')==3
  assert linearSearch('cinema')==-1
  assert linearSearch('theatre')==4
  assert linearSearch('school')==0
output: def linearSearch(search_item):
      array = ['school', 'hospital', 'bookstore', 'mall', 'theatre']
      for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1