How do I implement a sliding window in Python?
Question: I have a matrix for instance

    
    
    a=[12,2,4,67,8,9,23]
    

and I would like a code that appends a value say 45 to it and removes the
first value '12' so in essence I want to make

    
    
    a = [2,4,67,8,9,23,45]
    

I want to work with regular matrices not numpy matrices so I can't use hstack
or vstack How do I do this in python? Any help would be appreciated, thanks


Answer: Use a deque.

<http://docs.python.org/2/library/collections.html#collections.deque>

    
    
    >>> import collections
    >>> d = collections.deque(maxlen=7)
    >>> d.extend([12,2,4,67,8,9,23])
    >>> d.append(45)
    >>> print d
    deque([2, 4, 67, 8, 9, 23, 45], maxlen=7)
    

