def descendants_from_list(t, list_, arity):
"""
Populate Tree t's descendants from list_, filling them
in in level order, with up to arity children per node.
Then return t.
@param Tree t: tree to populate from list_
@param list list_: list of values to populate from
@param int arity: maximum branching factor
@rtype: Tree
>>> descendants_from_list(Tree(0), [1, 2, 3, 4], 2)
Tree(0, [Tree(1, [Tree(3), Tree(4)]), Tree(2)])
"""
q = Queue()
q.enqueue(t)
list_ = list_.copy()
while not q.is_empty(): # unlikely to happen
new_t = q.dequeue()
for i in range(0, arity):
if len(list_) == 0:
return t # our work here is done
else:
new_t_child = Tree(list_.pop(0))
new_t.children.append(new_t_child)
q.enqueue(new_t_child)
return t
class SingletonTestCase(unittest.TestCase):
'''Check whether enqueueing a single item makes it appear at the front.
'''
def setUp(self):
'''Set up a queue with a single element.
'''
self.queue = Queue()
self.queue.enqueue('a')
def tearDown(self):
'''Clean up.
'''
self.queue = None
def testIsEmpty(self):
'''Test is_empty() on non-empty Queue.
'''
self.assertFalse(self.queue.is_empty(),
'is_empty returned True on non-empty Queue!')
def testDequeue(self):
'''Test dequeue() on a non-empty Queue.
'''
front = self.queue.dequeue()
self.assertEqual(
front, 'a', 'The item at the front should have been "a" but was ' +
front + '.')
self.assertTrue(self.queue.is_empty(),
'Queue with one element not empty after dequeue().')
class TypicalTestCase(unittest.TestCase):
'''A comprehensive tester of typical behaviour of Queue.
'''
def setUp(self):
'''Set up an empty queue.
'''
self.queue = Queue()
def tearDown(self):
'''Clean up.
'''
self.queue = None
def testAll(self):
'''Check enqueueing and dequeueing several items.
'''
for item in range(20):
self.queue.enqueue(item)
self.assertFalse(
self.queue.is_empty(),
'Queue should not be empty after adding item ' + str(item))
item = 0
while not self.queue.is_empty():
front = self.queue.dequeue()
self.assertEqual(
front, item, 'Wrong item at the front of the Queue. Found ' +
str(front) + ' but expected ' + str(item))
item += 1
def descendents_from_list(t, L, arity):
''' (Tree, list, int) -> Tree
Populate t's descendents from L, filling them
in in level order, with up to arity children per node.
Then return t.
>>> descendents_from_list(Tree(0), [1, 2, 3, 4], 2)
Tree(0, [Tree(1, [Tree(3), Tree(4)]), Tree(2)])
'''
q = Queue()
q.enqueue(t)
L = L.copy()
while not q.is_empty(): # unlikely to happen
new_t = q.dequeue()
for i in range(0, arity):
if len(L) == 0:
return t # our work here is done
else:
new_t_child = Tree(L.pop(0))
new_t.children.append(new_t_child)
q.enqueue(new_t_child)
return t
def descendents_from_list(t, L, arity):
''' (Tree, list, int) -> Tree
Populate t's descendents from L, filling them
in in level order, with up to arity children per node.
Then return t.
>>> descendents_from_list(Tree(0), [1, 2, 3, 4], 2)
Tree(0, [Tree(1, [Tree(3), Tree(4)]), Tree(2)])
'''
q = Queue()
q.enqueue(t)
L = L.copy()
while not q.is_empty(): # unlikely to happen
new_t = q.dequeue()
for i in range(0,arity):
if len(L) == 0:
return t # our work here is done
else:
new_t_child = Tree(L.pop(0))
new_t.children.append(new_t_child)
q.enqueue(new_t_child)
return t
