def test_append():
L = LinkedList()
L.append_list("a")
L.append_list("b")
L.append_list("c")
actual = L.value_list()
print(actual)
expected = ["a", "b", "c"]
assert actual == expected
def test_insert_before():
L = LinkedList()
L.append_list("a")
L.append_list("b")
L.append_list("c")
L.insert_before("c", "z")
actual = L.value_list()
print(actual)
expected = ["a", "b", "z", "c"]
assert actual == expected
L.insert_before("a", "y")
actual = L.value_list()
print(actual)
expected = ["y", "a", "b", "z", "c"]
assert actual == expected
def zip_list(list_one, list_two):
# check if lists are linked lists
if type(list_one) != LinkedList or type(list_two) != LinkedList:
raise TypeError
# start at the beginning of each list
current_one = list_one.head
current_two = list_two.head
# create an empty linked list
zipped_list = LinkedList()
# while each node has is truthy
while current_one and current_two:
# append method adds new node and assigns appropriate next
zipped_list.append_list(current_one.value)
current_one = current_one.next_
# add list two node to zip, give it list two next
zipped_list.append_list(current_two.value)
current_two = current_two.next_
remainder = current_one if current_one else current_two
while remainder:
zipped_list.append_list(remainder.value)
remainder = remainder.next_
return zipped_list
