Can't push values in a queue and stuck on only first and last input(python)

Question

I've wanted to make simple queue with self parameter, however face with output problem in which my values I've added to the queue are only first and last on first and second positions, all in between is being ignored and placed zero's instead(as created).

class Queue():
    data = []
    r = 0
    f = 0
    maxSize = 0
    size = 0
    def __init__(self,maxSize):
        self.maxSize = maxSize
        self.data = [0.0]*maxSize

    def addValue(self, val):
        if self.size == self.maxSize:
            print('Queue overflow')
        else:
            self.data[self.r] = val
            self.r =+ 1
            self.size =+ 1

    def printQ(self):
        if self.size == 0:
            print('[]')
        else:
            print('[',end='')
            for i in range(0,len(self.data)):
                print(self.data[i],end=',')
            print(']')

myQueue = Queue(7)
print(myQueue.isEmpty())
myQueue.addValue(12)
myQueue.addValue(135)
myQueue.addValue(1)
myQueue.addValue(5)
myQueue.addValue(19)
myQueue.addValue(123)
myQueue.addValue(2222)

print(myQueue.isEmpty())
myQueue.printQ()

The output is:

True
False
[12,2222,0.0,0.0,0.0,0.0,0.0,]

As a style comment: -- your code seems to mix the usage of class variables and instance variables. There is a difference in their usage. You even have some variables as both class and instance variables (i.e. data, max_Size) which I wouldn't suggest since it creates confusing code. — DarrylG
– DarrylG, Commented Feb 1, 2022 at 13:32

Hussain Hassam · Accepted Answer · 2022-02-01 11:08:06Z

1

self.r =+ 1
self.size =+ 1

should be

self.r += 1
self.size += 1

You should also probably be assigning:

data = []
r = 0
f = 0
maxSize = 0
size = 0

all as instance variables in the constructor instead of declaring them as class variables

answered Feb 1, 2022 at 11:08

Hussain Hassam

3191 silver badge5 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

mozway Over a year ago

you might want to explicit that self.r =+ 1 is equivalent to self.r = (+1) ;)

Allan Chua · Accepted Answer · 2022-02-01 11:11:47Z

I don't know what is the use of the r and [0.0]*maxSize but this code works:

class Queue():
    data = []
    f = 0
    maxSize = 0
    size = 0

    def __init__(self,maxSize):
        self.maxSize = maxSize
        self.data = []

    def addValue(self, val):
        if self.size == self.maxSize:
            print('Queue overflow')
        else:
            self.data.append(val)
            self.size =+ 1

    def printQ(self):
        if self.size == 0:
            print('[]')
        else:
            print('[',end='')
            print(",".join(str(x) for x in self.data),end='')
            print(']')

    def isEmpty(self):
      return len(self.data) == 0

myQueue = Queue(7)
print(myQueue.isEmpty())
myQueue.addValue(12)
myQueue.addValue(135)
myQueue.addValue(1)
myQueue.addValue(5)
myQueue.addValue(19)
myQueue.addValue(123)
myQueue.addValue(2222)

print(myQueue.isEmpty())
myQueue.printQ()

# prints
# True
# False
# [12,135,1,5,19,123,2222,]

Collectives™ on Stack Overflow

Can't push values in a queue and stuck on only first and last input(python)

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related