def test_push_increases_the_stack_size():
stack = Stack()
previous_size = stack.size
stack.push(42)
assert stack.size == (previous_size + 1)
def test_push_items(self):
stack = Stack()
tests = [1, '0', Stack, lambda x: x, {}, [], None]
for test in tests:
stack.push(test)
assert len(tests) == len(stack)
def test_pop_all(self):
tests = [1, '0', Stack, lambda x: x, {}, [], None]
stack = Stack(tests)
assert len(stack) == len(tests)
stack.pop_all()
assert stack.is_empty() is True
def test_pop_items_with_initial_stack(self):
tests = [1, '0', Stack, lambda x: x, {}, [], None]
stack = Stack(tests)
assert len(stack) == len(tests)
for _ in tests:
stack.pop()
assert stack.is_empty() is True
def test_is_empty(self):
stack = Stack()
assert stack.is_empty() is True
stack.push(1)
assert stack.is_empty() is False
stack.pop()
assert stack.is_empty() is True
def test_str_prints_the_stack_and_its_elements():
stack = Stack()
stack.push(42)
stack.push("Second element")
stack.push(True)
assert str(stack) == "Stack(True, 'Second element', 42)"
def test_stack_push_pop_with_elements(self):
stack = Stack()
stack.push(1)
stack.push(2)
stack.push(5)
assert stack.pop() == 5
assert stack.pop() == 2
assert stack.pop() == 1
def eval_push_time_ratios(problem_size: int = 3000) -> Optional[TimeRatioType]:
"""
Function that calculates the execution time ratios, for the different time complexities.
Here, a process pool is created in order to speed up the process of generating
the lists of time ratios, for each time complexity.
"""
stack: Stack = Stack()
time_ratios: Dict[str, Union[str, List[Number]]] = {
func_name: [] for func_name in TIME_COMPLEXITIES
}
arguments: List[Any] = [
(stack, problem_size, function) for function in TIME_COMPLEXITIES
]
pool: ProcessPoolType = ProcessPool(get_cpu_count(), set_low_priority_to_process)
for response in pool.imap(_push_time_ratio_worker, arguments):
time_ratios.update(response)
time_ratios.update({
'data_struct_name': Stack.__name__.lower(),
'target_name': Stack.push.__name__,
})
return time_ratios
def test_size_returns_the_number_of_elements_in_the_stack():
stack = Stack()
stack.push(42)
stack.push(42)
stack.push(42)
assert stack.size == 3
def test_pop_decreases_the_stack_size():
stack = Stack()
stack.push(42)
previous_size = stack.size
stack.pop()
assert stack.size == (previous_size - 1)
def test_peek_does_not_change_the_stack_size():
stack = Stack()
stack.push(42)
previous_size = stack.size
stack.peek()
assert stack.size == previous_size
def test_size(self):
stack = Stack()
assert len(stack) == 0
stack.push(1)
assert len(stack) == 1
stack.pop()
assert len(stack) == 0
def test_stack_as_string(self):
stack = Stack()
assert str(stack) == ''
stack.push(3)
stack.push(1)
stack.push(2)
assert repr(stack) == '2 -> 1 -> 3'
def test_pop_items(self):
stack = Stack()
with self.assertRaises(StackPopException):
stack.pop()
one = 1
two = 2
stack.push(one)
stack.push(two)
assert len(stack) == 2
assert stack.pop() == two
assert stack.pop() == one
assert len(stack) == 0
def test_size_on_empty_stack_returns_zero():
stack = Stack()
assert stack.size == 0
def test_pop_returns_the_latest_element_pushed():
stack = Stack()
stack.push("First")
stack.push(42)
assert stack.pop() == 42
def test_peek_returns_the_element_on_top():
stack = Stack()
stack.push(42)
assert stack.peek() == 42
def test_push_one(self):
stack = Stack(lambda z: z)
assert len(stack) == 1
def step_impl(context):
context.stack = Stack()
def test_peek_on_empty_stack_returns_none():
stack = Stack()
assert stack.peek() == None
def test_push_sets_the_element_on_top():
stack = Stack()
stack.push(42)
assert stack.peek() == 42
def test_is_empty_returns_false_on_stack_with_elements():
stack = Stack()
stack.push(42)
assert not stack.is_empty()
def test_is_empty_returns_true_on_empty_stack():
stack = Stack()
assert stack.is_empty()