Array?

[Dr. Pastor]

I need a row of 127 bytes that I will use as a
circular buffer. Into the bytes (at unspecified times)
a mark (0<mark<128) will be written, one after the other.
After some time the "buffer" will contain the last 127 marks
and a pointer will point the next "usable" byte.
What would be the Pythonic way to do the above?
Thanks for any guidance.

[George Sakkis]

Re: Array?

Dr. Pastor wrote:
[color=blue]
> I need a row of 127 bytes that I will use as a
> circular buffer. Into the bytes (at unspecified times)
> a mark (0<mark<128) will be written, one after the other.
> After some time the "buffer" will contain the last 127 marks
> and a pointer will point the next "usable" byte.
> What would be the Pythonic way to do the above?
> Thanks for any guidance.[/color]

This will do the trick:

import itertools as it
from array import array

class CircularBuffer( object):
def __init__(self, size=128):
self._buffer = array('c', it.repeat(chr(0 ),size))
self._next = 0

def putmark(self, mark):
self._buffer[self._next] = mark
self._next = (self._next+1) % len(self._buffe r)

def __str__(self):
return '%s(%r)' % (self.__class__ .__name__,
self._buffer.to string())


if __name__ == '__main__':
import string
b = CircularBuffer( )
for c in string.letters * 10:
b.putmark(c)
print b


HTH,
George