Search for string

Define a function search_for_string that receives a list and a search term.
Use a loop to go through the list and see if the string is there. If it is,
return 'string found!'. If not, return 'string not found'


>>> search_for_string(['santiago', 'santi', 'santa'], 'santa')
'string found!''
>>> search_for_string(['a', 'b', 'c'], 'd')
'string not found'
>>> search_for_string([], 'a')
'string not found'
import unittest

class GetElementNumberListTestCase(unittest.TestCase):

    def test_string_in_list(self):
        self.assertEqual(search_for_string(['santiago', 'santi', 'santa'],
            'santa'), 'string found!')

    def test_string_present(self):
        self.assertEqual(search_for_string(['a', 'b', 'c'], 'd'),
            'string not found')

    def test_empty_list(self):
        self.assertEqual(search_for_string([], 'a'), 'string not found')