Queue Practice

Question:

Let's look at implementing queues in Python. Queue's are mentioned in Python's documentation . Examine the code below:

from collections import deque

From a library called collections , you can import a package called deque . As was mentioned in the video, a deque is a double-ended queue. You can enqueue on either end, but in the example you only enqueue one way and treat it as a normal queue.

Start Quiz:

algorithmsP4.py

"""Make a Queue class using a list!
Hint: You can use any Python list method
you'd like! Try to write each one in as 
few lines as possible.
Make sure you pass the test cases too!"""

class Queue:
    def __init__(self, head=None):
        self.storage = [head]

    def enqueue(self, new_element):
        pass

    def peek(self):
        pass 

    def dequeue(self):
        pass
    
# Setup
q = Queue(1)
q.enqueue(2)
q.enqueue(3)

# Test peek
# Should be 1
print q.peek()

# Test dequeue
# Should be 1
print q.dequeue()

# Test enqueue
q.enqueue(4)
# Should be 2
print q.dequeue()
# Should be 3
print q.dequeue()
# Should be 4
print q.dequeue()
q.enqueue(5)
# Should be 5
print q.peek()

Solution:

I managed to write all of the methods in one line!

class Queue(object):
    def __init__(self, head=None):
        self.storage = [head]

    def enqueue(self, new_element):
        self.storage.append(new_element)

    def peek(self):
        return self.storage[0]

    def dequeue(self):
        return self.storage.pop(0)