def __init__(self):
"""Initialise push and pop stacks
"""
# Create stack elements need to be on when adding to queue
self.add_stack = Stack()
# Create stack elements need to be on when removing from queue
self.remove_stack = Stack()
# Use boolean to track last operation
self.just_added = True
def test_peek():
s = Stack()
s.push("apple")
s.push("banana")
actual = s.peek()
expected = "banana"
assert actual == expected
def test_check_not_empty():
s = Stack()
s.push("apple")
s.push("banana")
actual = s.is_empty()
expected = False
assert actual == expected
def test_push_onto_full():
s = Stack()
s.push("apple")
s.push("banana")
s.push("cucumber")
actual = s.top.value
expected = "cucumber"
assert actual == expected
def __init__(self):
"""Initialise stack as is done for Stack, but also introduce stack
to track min values
"""
# Initialise Stack
super().__init__()
# Use this stack to track min vals
self.min_vals = Stack()
def test_pop_until_empty():
s = Stack()
s.push("apple")
s.push("banana")
s.push("cucumber")
s.pop()
s.pop()
s.pop()
actual = s.is_empty()
expected = True
assert actual == expected
def test_pop_some():
s = Stack()
s.push("apple")
s.push("banana")
s.push("cucumber")
s.pop()
actual = s.pop()
expected = "banana"
assert actual == expected
import pytest
from data_structures.stacks_and_queues.stack import Stack
from data_structures.stacks_and_queues.pseudo_queue import PseudoQueue, InvalidOperationError
test_stack = Stack()
test_stack.push(11)
test_stack.push(12)
test_stack.push(20)
@pytest.mark.skip
def test_enqueue():
q = PseudoQueue()
q.enqueue("apple")
actual = q.top.value
expected = "apple"
assert actual == expected
@pytest.mark.skip
def test_dequeue():
q = PseudoQueue()
q.enqueue("apple")
q.enqueue("banana")
actual = q.dequeue()
expected = "apple"
assert actual == expected
@pytest.mark.skip
def test_peek():
q = PseudoQueue()
q.enqueue("apple")
q.enqueue("banana")
def test_pop_empty():
s = Stack()
with pytest.raises(InvalidOperationError) as e:
s.pop()
assert str(e.value) == "Method not allowed on empty collection"
def test_push_onto_empty():
s = Stack()
s.push("apple")
actual = s.top.value
expected = "apple"
assert actual == expected
def test_pop_single():
s = Stack()
s.push("apple")
actual = s.pop()
expected = "apple"
assert actual == expected