def test_extend_empty_both_list(self):
linked_list = LinkedList()
linked_list1 = LinkedList()
linked_list1.extend(linked_list)
self.assertEqual(linked_list.head, None)
self.assertEqual(linked_list.tail, None)
def test_remove_empty_list(self):
"""Remove from an empty LinkedList."""
ll = LinkedList()
prestring = ll.__str__()
ll.remove(self.insert_float)
poststring = ll.__str__()
self.assertEqual(prestring, poststring)
def test_pop_from_empty_list(self):
"""Pop from a LinkedList that is empty."""
ll = LinkedList()
self.assertTrue(ll.head is None)
node = ll.pop()
self.assertTrue(node is None)
self.assertTrue(ll.head is None)
def test_first_item(self):
test_list = LinkedList()
test_list.insert_front(5)
self.assertEqual(5,
test_list.pop_front()._node_value,
"first item did not insert correctly")
def reverse_part_of_linked_list(head: LinkedList, start: int,
end: int) -> LinkedList:
if not head or start == end:
return head
outside_pointer = LinkedList(None)
outside_pointer.next = head
current_node = head
previous_node = outside_pointer
while start > 1:
previous_node = current_node
current_node = current_node.next
start -= 1
end -= 1
while end > 1:
next_node = current_node.next
current_node.next = next_node.next
next_node.next = previous_node.next
previous_node.next = next_node
end -= 1
return outside_pointer.next
def test_add_first_one_item():
linked_list = LinkedList()
linked_list.add_first(1)
assert len(linked_list) == 1
assert linked_list.head == 1
assert linked_list.tail == 1
def enqueue(self, value):
new_item = LinkedList(value)
new_item.previous = self._head
new_item.next = self._head.next
self._head.next.previous = new_item
self._head.next = new_item
self._size += 1
class Stack:
def __init__(self) -> None:
self._list = LinkedList()
def __len__(self) -> int:
return len(self._list)
def __iter__(self) -> Generator[T]:
for item in self._list:
yield item
def push(self, data: T) -> None:
self._list.add_first(data)
def peek(self) -> T:
if len(self._list) == 0:
raise IndexError("peek from empty list")
return self._list.head.data
def pop(self) -> T:
if len(self._list) == 0:
raise IndexError("pop from empty list")
data = self._list.head.data
self._list.remove_first()
return data
def test_append(self):
linked_list = LinkedList()
linked_list.append(data=0)
linked_list.append(data=1)
self.assertEqual(linked_list.head.data, 0)
self.assertEqual(linked_list.tail.data, 1)
self.assertNotEqual(linked_list.head, None)
self.assertNotEqual(linked_list.tail, None)
def test_kth_from_end_zero():
linked_list = LinkedList()
values = ["apples", "bananas", "cucumbers"]
for value in reversed(values):
linked_list.insert(value)
actual = linked_list.kth_from_end(0)
expected = "cucumbers"
assert actual == expected
def test_remove_item(self):
ll = LinkedList()
ll.add(1)
ll.add(2)
self.assertEqual(len(ll), 2)
ll.remove(1)
self.assertEqual(len(ll), 1)
def test_container():
linked_list = LinkedList()
linked_list.add_last(1)
linked_list.add_last(2)
assert 1 in linked_list
assert 2 in linked_list
assert 3 not in linked_list
def test_pop_from_one_list(self):
"""Pop from a LinkedList with one node."""
ll = LinkedList()
ll.insert(self.insert_string)
self.assertEqual(ll.head.value, self.insert_string)
node = ll.pop()
self.assertEqual(node.value, self.insert_string)
self.assertTrue(ll.head is None)
def test__get(constructor_arg):
ll = LinkedList(constructor_arg)
if constructor_arg:
for index, item in enumerate(constructor_arg):
assert isinstance(ll._get(index), LinkedListNode)
assert ll._get(index).value == item
else:
assert ll.head is None
def test_insert_at_index(self):
self.ll = LinkedList('Data1', 'Data2', 'Data3', 'Data4', 'Data5')
self.ll.insert_at_index(3, 'Data3.5')
self.assertEqual(self.ll[3], 'Data3.5', 'Insert at index should set the data at the index')
self.assertEqual(self.ll[2], 'Data3', 'Insert at index should not change the data at the index before it')
self.assertEqual(self.ll[4], 'Data4', 'Insert at index should move the other data up an index')
with self.assertRaises(IndexError, msg='Insert at out of bounds index should raise IndexError'):
self.ll.insert_at_index(len(self.ll) + 1, 'Data7')
def test_search():
items = range(10)
a_list = LinkedList(items)
# searching for a non-contained item returns None
assert a_list.search(object()) is None
# prove those values are searchable
for item in items:
assert a_list.search(item).data == item
def test_text_representation(self):
self.assertEqual(repr(self.ll), 'LinkedList()')
self.ll = LinkedList(1)
self.assertEqual(repr(self.ll), 'LinkedList(1)')
self.ll = LinkedList([1, 2, 3, 4])
self.assertEqual(repr(self.ll), 'LinkedList([1, 2, 3, 4])')
self.ll = LinkedList(1, 2, 3, 4)
self.assertEqual(repr(self.ll), 'LinkedList(1, 2, 3, 4)')
def test_iterate_over_linked_list():
my_list = LinkedList()
for i in range(5):
my_list.insert_before(i)
for el in my_list:
for el1 in my_list:
print('{} {}'.format(el, el1))
def test_node_removal(self):
self.ll = LinkedList(4, 7, 9, 11)
check_node = self.ll._get_node_at_index(2)
with self.assertRaises(ValueError):
self.ll._remove_node(self.ll.tail)
self.ll._remove_node(self.ll.head)
self.assertEqual(self.ll, LinkedList(7, 9, 11))
self.ll._remove_node(check_node)
self.assertEqual(self.ll, LinkedList(7, 11))
def test_insert_float_into_empty(self):
"""Insert into a LinkedList that is empty."""
ll = LinkedList()
self.assertTrue(ll.head is None)
ll.insert(self.insert_float)
self.assertEqual(ll.head.value, self.insert_float)
self.assertTrue(isinstance(ll.head.value, float))
self.assertTrue(ll.head.next is None)
def test_add_last_two_items():
linked_list = LinkedList()
linked_list.add_last(1)
linked_list.add_last(2)
assert len(linked_list) == 2
assert linked_list.head == 1
assert linked_list.tail == 2
assert linked_list.tail.next_ is None
def test_add_first_to_empty_list(self):
node1 = LinkedListNode("node 1")
my_linked_list = LinkedList()
my_linked_list.add_first(node1)
print(my_linked_list)
self.assertEqual(my_linked_list.head.node_value, 'node 1')
self.assertEqual(my_linked_list.head.next, None)
self.assertEqual(my_linked_list.tail.node_value, 'node 1')
self.assertEqual(my_linked_list.tail.next, None)
self.assertEqual(my_linked_list.length, 1)
def test_value_at(self):
linked_list = LinkedList()
linked_list.append(data=0)
linked_list.append(data=1)
linked_list.append(data=2)
linked_list.append(data=3)
linked_list.append(data=None)
self.assertEqual(linked_list.valueAt(1), 1)
self.assertEqual(linked_list.valueAt(0), 0)
self.assertEqual(linked_list.valueAt(3), 3)
def get_constants(self):
constants = LinkedList()
constants.push_back('pi')
constants.push_back('e')
constants.push_back('-pi')
constants.push_back('-e')
return constants
def test_search(self):
lst = LinkedList([82, 57, 16, 20, 21, 84, 99, 56, 100, 46])
node = lst.search(99)
self.assertEqual(node.data, 99)
node = lst.search(57)
self.assertEqual(node.data, 57)
node = lst.search(777)
self.assertIsNone(node)
def test_add_empty_both_list(self):
linked_list = LinkedList()
len1 = len(linked_list)
linked_list1 = LinkedList()
len2 = len(linked_list1)
linked_list2 = linked_list + linked_list1
self.assertEqual(linked_list2.head, None)
self.assertEqual(linked_list2.tail, None)
self.assertEqual(len(linked_list2), len1 + len2)
def test_insert_front(self):
#Arrange
linked_list = LinkedList()
#Act
linked_list.insert_front(1)
linked_list.insert_front(2)
#Assert
self.assertEqual(2, linked_list.head.value, "value is not correct")
def test_remove_list_with_value_at_tail(self):
"""Remove from a populated LinkedList a value it contains at its tail."""
ll = LinkedList()
ll.insert(self.insert_float)
ll.insert(self.insert_int)
ll.insert(self.insert_string)
ll.remove(self.insert_float)
expected = '(' + "'" + self.insert_string + "'" + ', ' + \
str(self.insert_int) + ')'
poststring = ll.__str__()
self.assertEqual(expected, poststring)
def test_delete_any(self):
test_list = LinkedList()
test_list.insert_front(5)
test_list.insert_front(7)
test_list.insert_front(9)
test_list.insert_front(7)
test_list.delete_item(7)
self.assertEqual(True, test_list.__contains__(7), "7 was not deleted")
class Stack:
def __init__(self):
self.list = LinkedList()
def push(self, item):
self.list.append_left(item)
def pop(self):
if self.list.n == 0:
raise EmptyStackException
return self.list.pop(0)
def test_reverse(self):
linked_list = LinkedList()
linked_list.append(data=0)
linked_list.append(data=1)
linked_list.append(data=2)
linked_list.append(data=3)
linked_list.append(data=4)
linked_list.reverse()
self.assertEqual(linked_list.head.data, 4)
self.assertEqual(linked_list.head.next.data, 3)
self.assertEqual(linked_list.head.next.next.data, 2)
self.assertEqual(linked_list.head.next.next.next.data, 1)
self.assertEqual(linked_list.tail.data, 0)
class FIFOQueue(object):
def __init__(self):
self.list = LinkedList()
def enqueue(self, item):
self.list.append_right(item)
def dequeue(self):
if not self.list.n:
raise EmptyQueueException
return self.list.pop(0)
def test_get_node_by_index(self):
node1 = LinkedListNode("node 1")
node2 = LinkedListNode("node 2")
my_linked_list = LinkedList()
my_linked_list.add_first(node1)
my_linked_list.add_last(node2)
print(my_linked_list)
with self.assertRaises(IndexError):
my_linked_list.get_node_by_index(2)
self.assertEqual(
my_linked_list.get_node_by_index(0).node_value, 'node 1')
self.assertEqual(
my_linked_list.get_node_by_index(1).node_value, 'node 2')
def test_init(self):
lst = LinkedList()
self.assertEqual(list(lst), [])
lst = LinkedList([])
self.assertEqual(list(lst), [])
lst = LinkedList([2, 5, 7, 10])
self.assertEqual(list(lst), [2, 5, 7, 10])
expected_list = [random.randint(0, 100) for _ in range(20)]
lst = LinkedList(expected_list)
self.assertEqual(list(lst), expected_list)
def test_reversing_list(self):
test_list = LinkedList()
test_list.insert_front(5)
test_list.insert_front(7)
test_list.insert_front(9)
test_list.reverse_list()
node = test_list.pop_front()
self.assertEqual(5, node._node_value, "list was not reversed")
def test_b_empty():
list_a = LinkedList()
for value in reversed([1, 2, 3]):
list_a.insert(value)
list_b = LinkedList()
actual = zip_lists(list_a, list_b)
expected = LinkedList()
for value in reversed([1, 2, 3]):
expected.insert(value)
assert str(actual) == str(expected)
def add_linked_lists(n1: LinkedList, n2: LinkedList) -> LinkedList:
result = LinkedList(None)
temp = result
carry_over = 0
while n1 is not None or n1 is not None or carry_over > 0:
if n1 is not None:
carry_over += n1.value
n1 = n1.next
if n2 is not None:
carry_over += n2.value
n2 = n2.next
carry_over, next_value = divmod(carry_over, 10)
temp.next = temp = LinkedList(next_value)
return result.next
def test_insert(self):
lst = LinkedList([82, 57, 16, 20, 21, 84, 99, 56, 100, 46])
inserted = lst.insert(7, 555)
self.assertTrue(inserted)
inserted = lst.insert(2, 86)
self.assertTrue(inserted)
inserted = lst.insert(200, 86)
self.assertFalse(inserted)
self.assertEqual(list(lst),
[82, 57, 86, 16, 20, 21, 84, 99, 555, 56, 100, 46])
def test_search_list_without_value(self):
"""Search a populated LinkedList for a value it doesn't contain."""
ll = LinkedList()
ll.insert(self.insert_float)
ll.insert(self.insert_int)
ll.insert(self.insert_string)
node = ll.search(self.value_not_in_list)
self.assertTrue(node is None)
def test_size_of_populated_list(self):
"""Get the size of a populated LinkedList."""
ll = LinkedList()
ll.insert(self.insert_float)
ll.insert(self.insert_int)
ll.insert(self.insert_string)
self.assertEqual(ll.head.value, self.insert_string)
self.assertEqual(ll.size(), 3)
def test_init(self):
ll = LinkedList()
self.assertTrue(ll.is_empty(), msg="initalizing an empty linked list should be empty")
ll = LinkedList('Data')
self.assertFalse(ll.is_empty(), msg="initalizing a linked list with one element should not be empty")
ll = LinkedList(['Data', 'Data2'])
self.assertFalse(ll.is_empty(), msg="initalizing a linked list with one list should not be empty")
ll = LinkedList('Data', 'Data2', 'Data3')
self.assertFalse(ll.is_empty(), msg="initalizing a linked list with multiple element should not be empty")
def test_partition_around_x(self):
self.linky = LinkedList()
l = [1, 2, 3, 4, 5, 6, 7, 5, 8, 9, 10]
for i in range(len(l)):
self.linky.insert(l[i])
self.linky.partition_around_x(5)
self.assertListEqual([1, 2, 3, 4, 5, 5, 10, 9, 8, 7, 6],
self.linky.print_me())
def test_str_many_list(self):
"""Get the string representation of a LinkedList with many values."""
ll = LinkedList()
ll.insert(self.insert_float)
ll.insert(self.insert_int)
ll.insert(self.insert_string)
self.assertEqual(ll.__str__(), '(' + "'" + self.insert_string +
"', " + str(self.insert_int) + ', ' + str(self.insert_float) +
')')
def test_search_list_with_value_at_tail(self):
"""Search a populated LinkedList for a value it contains at its tail."""
ll = LinkedList()
ll.insert(self.insert_float)
ll.insert(self.insert_int)
ll.insert(self.insert_string)
node = ll.search(self.insert_float)
self.assertTrue(isinstance(node, LinkedListNode))
self.assertEqual(node.value, self.insert_float)
def test_insert_float_into_populated(self):
"""Insert into a LinkedList that is already populated with some
values
"""
ll = LinkedList()
ll.insert(self.insert_float)
ll.insert(self.insert_int)
ll.insert(self.insert_string)
self.assertEqual(ll.head.value, self.insert_string)
ll.insert(self.insert_float)
self.assertEqual(ll.head.value, self.insert_float)
self.assertTrue(isinstance(ll.head.value, float))
self.assertEqual(ll.head.next.value, self.insert_string)
def test_pop_from_many_list(self):
"""Pop from a LinkedList with many nodes."""
ll = LinkedList()
ll.insert(self.insert_float)
ll.insert(self.insert_int)
ll.insert(self.insert_string)
self.assertEqual(ll.head.value, self.insert_string)
node = ll.pop()
self.assertEqual(node.value, self.insert_string)
self.assertEqual(ll.head.value, self.insert_int)
def test_rem_dups(self):
self.linky = LinkedList()
self.linky.insert(1)
self.linky.insert(1)
self.linky.insert(2)
self.linky.insert(2)
self.linky.insert(3)
self.linky.insert(3)
self.linky.rem_dups()
self.assertListEqual([3, 2, 1], self.linky.print_me())
def test_merge(self):
self.ll = LinkedList(4, 7, 9, 11)
self.assertEqual(self.ll.merge(LinkedList(2, 5, 6, 12, 15, 16)),
LinkedList(2, 4, 5, 6, 7, 9, 11, 12, 15, 16),
'Merge linked lists should return a sorted linked list')
self.assertEqual(self.ll.merge(LinkedList(5, 12, 15, 16)),
LinkedList(4, 5, 7, 9, 11, 12, 15, 16),
'Merge linked lists should return a sorted linked list')
self.assertEqual(self.ll.merge(LinkedList()),
LinkedList(4, 7, 9, 11),
'Merge linked lists should return a sorted linked list')
def test_remove_index(self):
ll = LinkedList()
ll.add(1)
ll.add(2)
ll.remove_item_at(0)
self.assertEqual(ll.get_item_at(0), 2)
def test_get_slices(self):
self.ll = LinkedList(1, 2, 3, 4, 5)
self.assertEqual(self.ll[:], LinkedList(1, 2, 3, 4, 5), "Get slice '[:]' should return a shallow copy of the list")
self.assertEqual(self.ll[2:], LinkedList(3, 4, 5), "Get slice '[2:]' should return a shallow subcopy of the list")
self.assertEqual(self.ll[:2], LinkedList(1, 2), "Get slice '[:2]' should return a shallow subcopy of the list")
self.assertEqual(self.ll[1:3], LinkedList(2, 3), "Get slice '[1:3]' should return a shallow subcopy of the list")
self.assertEqual(self.ll[1:1], LinkedList(), "Get slice '[1:1]' should return an empty linked list")
self.assertEqual(self.ll[5:], LinkedList(), "Get slice '[5:]' should return an empty linked list")
self.assertEqual(self.ll[-3:], LinkedList(3, 4, 5), "Get slice '[-3:]' should return a shallow subcopy of the list")
self.assertEqual(self.ll[:-3], LinkedList(1, 2), "Get slice '[:-3]' should return a shallow subcopy of the list")
self.assertEqual(self.ll[-4:-2], LinkedList(2, 3), "Get slice '[-4:-2]' should return a shallow subcopy of the list")
self.assertEqual(self.ll[-2:-2], LinkedList(), "Get slice '[:2]' should return a shallow subcopy of the list")
self.assertEqual(self.ll[:-5], LinkedList(), "Get slice '[:-5]' should return an empty linked list")
self.assertEqual(self.ll[1:-5], LinkedList(), "Get slice '[1:-5]' should return an empty linked list, values stop is less than start")
self.assertEqual(self.ll[::-1], LinkedList(5, 4, 3, 2, 1))
def test_remove_items(self):
with self.assertRaises(ValueError, msg='Remove functions should raise ValueError on empty linked list'):
self.ll.remove_item(None)
with self.assertRaises(ValueError, msg='Remove functions should raise ValueError on empty linked list'):
self.ll.remove_head()
with self.assertRaises(ValueError, msg='Remove functions should raise ValueError on empty linked list'):
self.ll.remove_tail()
self.ll = LinkedList(1, 2, 3, 4, 5, 3)
self.ll.remove_item(2)
self.assertFalse(2 in self.ll)
self.ll.remove_item(3)
self.assertTrue(3 in self.ll)
self.ll.remove_head()
self.assertEqual(self.ll['head'], 4)
with self.assertRaises(ValueError):
self.ll.remove_item('None')
with self.assertRaises(ValueError):
self.ll.remove_item(None)
def test_get(self):
with self.assertRaises(IndexError, msg="Get at head/tail from empty linked list should return IndexError"):
self.ll.get_at_head()
self.ll.get_at_tail()
self.ll = LinkedList(1, 2, 3, 4)
self.assertEqual(self.ll.get_at_head(), 1, 'Get at head should get head data')
self.assertEqual(self.ll.get_at_tail(), 4, 'Get at tail should get tail data')
self.assertEqual(self.ll.get_at_index(0), 1, 'Get at index 0 should get first item')
self.assertEqual(self.ll.get_at_index(2), 3, 'Get at index 2 should get third item')
self.assertEqual(self.ll.get_at_index(2), self.ll[2])
self.assertEqual(self.ll.get_at_head(), self.ll['head'])
self.assertEqual(self.ll.get_at_tail(), self.ll['tail'])
with self.assertRaises(IndexError, msg='Get at out of bounds index should throw an IndexError'):
self.ll[len(self.ll)]
self.assertEqual(self.ll[-1], 4, 'Get at index -1 should return tail item')
self.assertEqual(self.ll[-2], 3, 'Get at index -2 should return tail item')
self.assertEqual(self.ll[len(self.ll) - 1], 4, 'Get at last index should return tail item')
self.assertEqual(self.ll[-len(self.ll)], 1, 'Get at index (-length of list) should return head item')
def test_remove():
items = list(range(10))
a_list = LinkedList(items)
# removing a value that isn't in it should return false
assert a_list.remove(object()) is False
assert list(a_list) == list(reversed(items))
# get 7 and remove it
seven = a_list.search(7)
assert a_list.remove(seven) is True
assert list(a_list) == [9, 8, 6, 5, 4, 3, 2, 1, 0]
# remove all the even-numbered values
for node in a_list:
if node & 1 == 0:
assert a_list.remove(a_list.search(node)) is True
assert list(a_list) == [9, 5, 3, 1]
def setUp(self):
self.LinkedList = LinkedList()
self.values = [-3.0, 'new', [], {'test': 1}]
def test_single_item(self):
ll = LinkedList()
ll.add(1)
self.assertEqual(len(ll), 1)
def test_insert():
a_list = LinkedList()
a_list.insert(1)
assert list(a_list) == [1]
assert a_list.size() == 1
def test_pop(items):
s = LinkedList(items)
for item in reversed(items):
assert s.pop() == item
with pytest.raises(IndexError):
s.pop()
def test_display(items, capfd):
a_list = LinkedList(items)
a_list.display()
out, err = capfd.readouterr()
assert out == str(tuple(reversed(items))) + '\n'
assert not err
