from __future__ import print_function
import time
from myqueue import Queue
Q = Queue()
Q.append(10)
Q.append(20)
print(Q.peek())
print(Q.pop())
print(Q.pop())
try:
print(Q.pop())
except IndexError as e:
print("Error message:", e) # Prints "Queue is empty"
i = 10000
values = range(i)
start_time = time.time()
Q.extend(values)
end_time = time.time() - start_time
print("Adding {} items took {:1.3f} msecs.".format(i, 1000 * end_time))
for i in range(41):
class Handler:
""" Handler class """
_OPTIONS = {
"1": "add_to_queue",
"2": "remove_from_queue",
"3": "get_first_item",
"4": "get_queue_size",
"5": "is_queue_empty",
"q": "quit"
}
def __init__(self):
""" Initialize class """
self.queue = Queue()
self.start()
def _get_method(self, method_name):
"""
Uses function getattr() to dynamically get value of an attribute.
"""
return getattr(self, self._OPTIONS[method_name])
def _print_menu(self):
"""
Use docstring from methods to print options for the program.
"""
menu = ""
for key in sorted(self._OPTIONS):
method = self._get_method(key)
docstring = inspect.getdoc(method)
menu += "{choice}: {explanation}\n".format(
choice=key,
explanation=docstring
)
print(chr(27) + "[2J" + chr(27) + "[;H")
print(menu)
def add_to_queue(self):
""" Adds a node to the queue. """
value = input("\nAdd a value: \n>>> ")
self.queue.enqueue(value)
print(f"{value} has been added.")
def remove_from_queue(self):
""" Removes the first node from the queue. """
try:
print(f"{self.queue.dequeue()} has been removed.")
except EmptyQueueException as e:
print(f"Error: {e}")
def get_first_item(self):
""" Prints the value of the first queue node. """
try:
print(self.queue.peek())
except EmptyQueueException as e:
print(f"Error: {e}")
def get_queue_size(self):
""" Shows the queue length. """
print(self.queue.size())
def is_queue_empty(self):
""" Shows if the queue is empty or not. """
print(self.queue.is_empty())
@staticmethod
def quit():
""" Quit the program """
sys.exit()
def start(self):
""" Start method """
while True:
self._print_menu()
choice = input("Enter menu selection:\n-> ")
try:
self._get_method(choice.lower())()
except KeyError:
print("Invalid choice!")
input("\nPress any key to continue ...")