def test_contains(self):
     ht = HashTable()
     ht.set('I', 1)
     ht.set('V', 5)
     ht.set('X', 10)
     assert ht.contains('I') is True
     assert ht.contains('V') is True
     assert ht.contains('X') is True
     assert ht.contains('A') is False
 def test_delete(self):
     ht = HashTable()
     ht.set('I', 1)
     ht.set('V', 5)
     ht.set('X', 10)
     assert ht.length() == 3
     ht.delete('I')
     ht.delete('X')
     assert ht.length() == 1
     with self.assertRaises(KeyError):
         ht.delete('X')  # Key no longer exists
     with self.assertRaises(KeyError):
         ht.delete('A')  # Key does not exist
 def test_set_twice_and_get(self):
     ht = HashTable()
     ht.set('I', 1)
     ht.set('V', 4)
     ht.set('X', 9)
     assert ht.length() == 3
     ht.set('V', 5)  # Update value
     ht.set('X', 10)  # Update value
     assert ht.get('I') == 1
     assert ht.get('V') == 5
     assert ht.get('X') == 10
     assert ht.length() == 3  # Check length is not overcounting
 def test_set_and_get(self):
     ht = HashTable()
     ht.set('I', 1)
     ht.set('V', 5)
     ht.set('X', 10)
     assert ht.get('I') == 1
     assert ht.get('V') == 5
     assert ht.get('X') == 10
     assert ht.length() == 3
     with self.assertRaises(KeyError):
         ht.get('A')  # Key does not exist
 def test_length(self):
     ht = HashTable()
     assert ht.length() == 0
     ht.set('I', 1)
     assert ht.length() == 1
     ht.set('V', 5)
     assert ht.length() == 2
     ht.set('X', 10)
     assert ht.length() == 3
 def test_items(self):
     ht = HashTable()
     assert ht.items() == []
     ht.set('I', 1)
     assert ht.items() == [('I', 1)]
     ht.set('V', 5)
     self.assertCountEqual(ht.items(), [('I', 1), ('V', 5)])
     ht.set('X', 10)
     self.assertCountEqual(ht.items(), [('I', 1), ('V', 5), ('X', 10)])
 def test_values(self):
     ht = HashTable()
     assert ht.values() == []
     ht.set('I', 1)
     assert ht.values() == [1]
     ht.set('V', 5)
     self.assertCountEqual(ht.values(), [1, 5])  # Ignore item order
     ht.set('X', 10)
     self.assertCountEqual(ht.values(), [1, 5, 10])  # Ignore item order
 def test_keys(self):
     ht = HashTable()
     assert ht.keys() == []
     ht.set('I', 1)
     assert ht.keys() == ['I']
     ht.set('V', 5)
     self.assertCountEqual(ht.keys(), ['I', 'V'])  # Ignore item order
     ht.set('X', 10)
     self.assertCountEqual(ht.keys(), ['I', 'V', 'X'])  # Ignore item order
 def test_init(self):
     ht = HashTable(4)
     assert len(ht.buckets) == 4
     assert ht.length() == 0