CODEWITHSUNDEEP
pythonqueue
Irina
Irina

Reputation: 31

Initialising Queue in Python

I am trying to code my first Queue class. So far I have this code that seemes to work: 

class Queue(list):
    def __init__(self):
        self = []

    def insert(self, x):
        self.append(x)
        return self

    def delete(self):
        if len(self) == 0:
            print "The queue is empty"
        else:
            self.remove(self[0])
            return self

However, I was recomended to rewrite it, and when I try something like this I got wrong results: 

class Queue:
    def __init__(self):
        self.items = []

    def insert(self, x):
        self.items.append(x)

Test:

queue = Queue()
print queue
queue.insert(5)
print queue

Got:

<__main__.Queue instance at 0x0000000002A2F148>
<__main__.Queue instance at 0x0000000002A2F148>

Could you, please, explain me the difference between two approaches and why the second doesn't work (although I saw it on many websites)?

Upvotes: 3

Views: 1260

Answers (2)

dlmeetei
dlmeetei

Reputation: 10391

You need need implement either str or repr for your class Queue before printing

Upvotes: 1

JustDucky
JustDucky

Reputation: 132

Inside the rewrite, you might want to return the value of insert, and in the calling, assign it to a variable:

queue = Queue()
print queue #should show something like <__main__.Queue instance at 0x(some numbers here)>
newQueue = queue.insert(5)
print newQueue

and inside the function, changing it to something like:

def insert(self, x):
    self.items.append(x)
    return self.items

Upvotes: 0

Related Questions