class test_hashmap(unittest.TestCase):
"""
Test class for class Hashmap
In all the quadratic probing tests unexpected errors can occur, for example
if size of hashmap is small even one element can fill up a significant amount
of size of the hashmap. Therefore I didn't use loop testing in quadratic probing
it was causing random errors!
"""
def setUp(self):
size = math.floor(
random.random() *
30) + 30 # minimum size 15 to avoid coflicts with line 26
self._dict = HashMap(size, probing='quadratic', verbose=False)
def test_hash_index(self):
idx = self._dict.hash_index('divyansh')
verify = 'divyansh'.__hash__() & (
self._dict.size - 1
) # __hash__ returns different hashes for different python runs
self.assertEqual(idx, verify)
def test_sanity_check_key(self):
self.assertRaises(ValueError, self._dict.sanity_check_key,
23) # passed any number to raise exception
self.assertRaises(ValueError, self._dict.sanity_check_key,
[2, 3, 4]) # passed a list to raise exception
self.assertRaises(ValueError, self._dict.sanity_check_key,
('asd', 'asd')) # passed a tuple to raise exception
def test_probe_linear(self):
self._dict.probing = 'linear'
num = self._dict.probe(5)
self.assertEqual(num, 6)
self._dict.ctr = 1
num = self._dict.probe(self._dict.size + 3)
self.assertEqual(num, 4)
def test_probe_quadratic(self):
self._dict.probing = 'quadratic'
self.assertEqual(self._dict.probe(5), 6)
self.assertEqual(self._dict.probe(6), 10)
self.assertEqual(self._dict.probe(1), 10)
self._dict.reset()
self.assertEqual(self._dict.probe(self._dict.size - 1), 0)
self.assertEqual(self._dict.probe(self._dict.size - 1), 3)
def test_set_quadratic(self):
self.assertEqual(self._dict.set('animal', 'monkey'), True)
self.assertEqual(self._dict.set('animal', 'lion'), True)
self.assertRaises(ValueError, self._dict.set, 23, 'twenty_three')
def test_set_linear(self):
self._dict.probing = 'linear'
self.assertEqual(self._dict.set('animal', 'monkey'), True)
self.assertEqual(self._dict.set('animal', 'lion'), True)
self.assertRaises(ValueError, self._dict.set, 23, 'twenty_three')
self._dict.reset()
for i in range(self._dict.size):
self.assertEqual(
self._dict.set('animal' + str(i), 'monkey' + str(i)), True)
self.assertEqual(self._dict.load(), 1)
self.assertEqual(
self._dict.set('one_more_key_to_cause_overflow', 'monkey_n'),
False)
def test_get_quadratic(self):
self.probing = 'quadratic'
self.assertEqual(self._dict.set('animal' + str(3), 'monkey' + str(3)),
True)
self.assertEqual(self._dict.get('animal' + str(3)), 'monkey' + str(3))
self.assertRaises(KeyError, self._dict.get, 'bird')
def test_get_linear(self):
self._dict.probing = 'linear'
for i in range(self._dict.size):
self.assertEqual(
self._dict.set('animal' + str(i), 'monkey' + str(i)), True)
for i in reversed(range(self._dict.size)):
self.assertEqual(self._dict.get('animal' + str(i)),
'monkey' + str(i))
self.assertRaises(KeyError, self._dict.get, 'bird')
def test_delete_quadratic(self):
self._dict.probing = 'quadratic'
self._dict.set('animal', 'monkey')
self._dict.delete('animal')
self.assertRaises(KeyError, self._dict.get, 'animal')
def test_delete_linear(self):
self._dict.probing = 'linear'
self._dict.set('animal', 'monkey')
self._dict.delete('animal')
for i in range(self._dict.size):
self.assertEqual(
self._dict.set('animal' + str(i), 'monkey' + str(i)), True)
for i in reversed(range(self._dict.size)):
self.assertEqual(self._dict.delete('animal' + str(i)), None)
self.assertRaises(KeyError, self._dict.delete, 'animal' + str(i))
self.assertRaises(KeyError, self._dict.get, 'animal')
def test_load_quadratic(self):
self.probing = 'quadratic'
itr = math.floor(random.random() * self._dict.size / 2 + 5)
for i in range(itr):
random_key = ''.join(
random.choices(string.ascii_uppercase + string.digits, k=15))
self._dict.set(random_key, 'monkey' + str(i))
load_value = self._dict.load()
self.assertLessEqual(load_value, 0.6)
def test_load_linear(self):
self.probing = 'linear'
itr = math.floor(random.random() * self._dict.size + 5)
for i in range(itr):
random_key = ''.join(
random.choices(string.ascii_uppercase + string.digits, k=15))
self._dict.set(random_key, 'monkey' + str(i))
load_value = self._dict.load()
self.assertLessEqual(load_value, 1)
