input: Write a function called list_generator that takes a single parameter input_list, which is expected to be a list of numbers. The function should return a generator that yields each item from the input_list. If the input_list is empty, the generator should yield no items.
  
  assert list(list_generator([1,3,5,7,9]))==[1,3,5,7,9]
  assert list(list_generator([2,4,6,8]))==[2,4,6,8]
  assert list(list_generator([]))==[]
output: def list_generator(input_list):
      for item in input_list:
          yield item