def test_if_peek_needs_no_inputs():
"""Test that an unnecessary parameter will raise a TypeError."""
import pytest
from que_ import Queue
q = Queue()
q.enqueue(5)
with pytest.raises(TypeError):
q.peek(5)
def test_5(self):
""" Check that peek gives the value of the top node """
q = Queue()
n1 = Node(1)
n2 = Node(2)
q.enqueue(n1)
q.enqueue(n2)
q.peek()
self.assertEqual(q.top._value, 1)
def test_peek():
"""Test if next value to be removed is accurate."""
from que_ import Queue
test_q = Queue()
test_q.enqueue(99)
test_q.enqueue(5)
assert test_q.peek() == 99
def test_queue_peek_with_data():
"""Test the queue peek method displays the tail."""
from que_ import Queue
q = Queue()
q.enqueue('one')
q.enqueue('two')
assert q.peek() == 'one'
def breadth_first_traversal(self, val):
"""
Perform a breadth first traversal.
The breadth first traversal starts at the user input val
and explores the neighbor nodes first before moving on to
the next depth of neighbors.
"""
search_order = []
children_queue = Queue()
children_queue.enqueue(val)
while children_queue.peek():
if self.graph[children_queue.peek()] == {}:
child = children_queue.dequeue()
if child not in search_order:
search_order.append(child)
else:
for child in self.graph[children_queue.peek()].keys():
if child not in search_order:
children_queue.enqueue(child)
search_order.append(children_queue.dequeue())
return search_order
def breadth_first(self):
"""Return a generator that returns values tree breadth first order."""
if self.size_count == 0:
raise IndexError("Cannot traverse empty tree.")
breadth_list = Queue()
breadth_list.enqueue(self.root)
yield breadth_list.peek().val
while breadth_list.peek():
if breadth_list.peek().left:
breadth_list.enqueue(breadth_list.peek().left)
yield breadth_list.peek().left.val
if breadth_list.peek().right:
breadth_list.enqueue(breadth_list.peek().right)
yield breadth_list.peek().right.val
breadth_list.dequeue()
def test_output_of_peek_exists():
"""Test that the output exists."""
from que_ import Queue
q = Queue()
q.enqueue(5)
assert q.peek() is not None
def test_peek_finds_value_of_front_of_queue(itr):
"""Test that peek finds the value of the front of the queue."""
from que_ import Queue
q = Queue(itr)
assert q.peek() == itr[0]
assert q._values.length == len(itr)
def test_peek_empty():
"""Test calling peek on empty returns None."""
from que_ import Queue
test_q = Queue()
assert test_q.peek() is None
def test_queue_peek_with_no_data():
"""Test the queue peek returns None."""
from que_ import Queue
q = Queue()
assert q.peek() is None