CODEWITHSUNDEEP
pythonpython-3.x
rggod
rggod

Reputation: 629

In python, how to use queues properly?

So far I have the following:

fnamw = input("Enter name of file:")
def carrem(fnamw):
    s = Queue( )
    for line in fnamw:
        s.enqueue(line)
    return s

 print(carrem(fnamw))

The above doesn't print a list of the numbers in the file that I input instead the following is obtained:

<__main__.Queue object at 0x0252C930>

Upvotes: 0

Views: 120

Answers (2)

Dolda2000
Dolda2000

Reputation: 25855

It seems to me that you don't actually have any need for a Queue in that program. A Queue is used primarily for synchronization and data transfer in multithreaded programming. And it really doesn't seem as if that is what you're attempting to do.

For you usage, you could just as well use an ordinary Python list:

fnamw = input("Enter name of file:")
def carrem(fnamw):
    s = []
    for line in fnamw:
        s.append(line)
    return s

print(carrem(fnamw))

On that same note, however, you're not actually reading the file. The program as you quoted it will simply put each character in the filename as a post of its own into the list (or Queue). What you really want is this:

def carrem(fnamw):
    s = []
    with open(fnamw) as fp:
        for line in fp:
            s.append(line)
    return s

Or, even simpler:

def carrem(fnamw):
    with open(fnamw) as fp:
        return list(fp)

Upvotes: 1

Slater Victoroff
Slater Victoroff

Reputation: 21904

When printing a Queue, you're just printing the object directly, which is why you get that result.

You don't want to print the object representation, but I'm assuming you want to print the contents of the Queue. To do so you need to call the get method of the Queue. It's worth noting that in doing so, you will exhaust the Queue.

Replacing print(carrem(fnamw)) with print(carrem(fnamw).get()) should print the first item of the Queue.

If you really just want to print the list of items in the Queue, you should just use a list. Queue are specifically if you're looking for a FIFO (first-in-first-out) data structure.

Upvotes: 1

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