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73 changes: 36 additions & 37 deletions koans/about_lists.py
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ class AboutLists(Koan):
def test_creating_lists(self):
empty_list = list()
self.assertEqual(list, type(empty_list))
self.assertEqual(__, len(empty_list))
self.assertEqual(0, len(empty_list))

def test_list_literals(self):
nums = list()
Expand All @@ -21,89 +21,88 @@ def test_list_literals(self):
self.assertEqual([1], nums)

nums[1:] = [2]
self.assertListEqual([1, __], nums)
self.assertListEqual([1, 2], nums)

nums.append(333)
self.assertListEqual([1, 2, __], nums)
self.assertListEqual([1, 2, 333], nums)

def test_accessing_list_elements(self):
noms = ['peanut', 'butter', 'and', 'jelly']

self.assertEqual(__, noms[0])
self.assertEqual(__, noms[3])
self.assertEqual(__, noms[-1])
self.assertEqual(__, noms[-3])
self.assertEqual('peanut', noms[0])
self.assertEqual('jelly', noms[3])
self.assertEqual('jelly', noms[-1])
self.assertEqual('butter', noms[-3])

def test_slicing_lists(self):
noms = ['peanut', 'butter', 'and', 'jelly']

self.assertEqual(__, noms[0:1])
self.assertEqual(__, noms[0:2])
self.assertEqual(__, noms[2:2])
self.assertEqual(__, noms[2:20])
self.assertEqual(__, noms[4:0])
self.assertEqual(__, noms[4:100])
self.assertEqual(__, noms[5:0])
self.assertEqual(['peanut'], noms[0:1])
self.assertEqual(['peanut', 'butter'], noms[0:2])
self.assertEqual([], noms[2:2])
self.assertEqual(['and', 'jelly'], noms[2:20])
self.assertEqual([], noms[4:0])
self.assertEqual(['jelly'], noms[4:100])
self.assertEqual([], noms[5:0])

def test_slicing_to_the_edge(self):
noms = ['peanut', 'butter', 'and', 'jelly']

self.assertEqual(__, noms[2:])
self.assertEqual(__, noms[:2])
self.assertEqual(['and', 'jelly'], noms[2:])
self.assertEqual(['peanut', 'butter'], noms[:2])

def test_lists_and_ranges(self):
self.assertEqual(range, type(range(5)))
self.assertNotEqual([1, 2, 3, 4, 5], range(1,6))
self.assertEqual(__, list(range(5)))
self.assertEqual(__, list(range(5, 9)))
self.assertNotEqual([1, 2, 3, 4, 5], list(range(1, 6)))
self.assertEqual([0, 1, 2, 3, 4], list(range(5)))
self.assertEqual([5, 6, 7, 8], list(range(5, 9)))

def test_ranges_with_steps(self):
self.assertEqual(__, list(range(5, 3, -1)))
self.assertEqual(__, list(range(0, 8, 2)))
self.assertEqual(__, list(range(1, 8, 3)))
self.assertEqual(__, list(range(5, -7, -4)))
self.assertEqual(__, list(range(5, -8, -4)))
self.assertEqual([5, 4], list(range(5, 3, -1)))
self.assertEqual([0, 2, 4, 6], list(range(0, 8, 2)))
self.assertEqual([1, 4, 7], list(range(1, 8, 3)))
self.assertEqual([5, 1, -3], list(range(5, -7, -4)))
self.assertEqual([5, 1, -3, -7], list(range(5, -8, -4)))

def test_insertions(self):
knight = ['you', 'shall', 'pass']
knight.insert(2, 'not')
self.assertEqual(__, knight)
self.assertEqual(['you', 'shall', 'not', 'pass'], knight)

knight.insert(0, 'Arthur')
self.assertEqual(__, knight)
self.assertEqual(['Arthur', 'you', 'shall', 'not', 'pass'], knight)

def test_popping_lists(self):
stack = [10, 20, 30, 40]
stack.append('last')

self.assertEqual(__, stack)
self.assertEqual([10, 20, 30, 40, 'last'], stack)

popped_value = stack.pop()
self.assertEqual(__, popped_value)
self.assertEqual(__, stack)
self.assertEqual('last', popped_value)
self.assertEqual([10, 20, 30, 40], stack)

popped_value = stack.pop(1)
self.assertEqual(__, popped_value)
self.assertEqual(__, stack)
self.assertEqual(20, popped_value)
self.assertEqual([10, 30, 40], stack)

# Notice that there is a "pop" but no "push" in python?

# Part of the Python philosophy is that there ideally should be one and
# only one way of doing anything. A 'push' is the same as an 'append'.

# To learn more about this try typing "import this" from the python
# To learn more about this, try typing "import this" from the Python
# console... ;)

def test_making_queues(self):
queue = [1, 2]
queue.append('last')

self.assertEqual(__, queue)
self.assertEqual([1, 2, 'last'], queue)

popped_value = queue.pop(0)
self.assertEqual(__, popped_value)
self.assertEqual(__, queue)
self.assertEqual(1, popped_value)
self.assertEqual([2, 'last'], queue)

# Note, popping from the left hand side of a list is
# Note, popping from the left-hand side of a list is
# inefficient. Use collections.deque instead.