Python circular buffer

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Here is a simple circular buffer, or ring buffer, implementation in Python. It is a first-in, first-out (FIFO) buffer with a fixed size.

class RingBuffer:
    def __init__(self, size):
        self.data = [None for i in xrange(size)]

    def append(self, x):
        self.data.pop(0)
        self.data.append(x)

    def get(self):
        return self.data

Here is an example where the buffer size is 4. Ten integers, 0-9, are inserted, one at a time, at the end of the buffer. Each iteration, the first element is removed from the front of the buffer.

buf = RingBuffer(4)
for i in xrange(10):
    buf.append(i)
    print buf.get()

Here are the results:

[None, None, None, 0]
[None, None, 0, 1]
[None, 0, 1, 2]
[0, 1, 2, 3]
[1, 2, 3, 4]
[2, 3, 4, 5]
[3, 4, 5, 6]
[4, 5, 6, 7]
[5, 6, 7, 8]
[6, 7, 8, 9]

References:

• http://mail.python.org/pipermail/python-dev/2003-April/thread.html#34790
• http://www.wayforward.net/pycontract/examples/circbuf.py
• http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/68429
• http://docs.python.org/tut/node7.html#SECTION007120000000000000000
• http://docs.python.org/lib/module-Queue.html
• http://en.wikipedia.org/wiki/Circular_queue