Array? Please help.

[George Sakkis]

Diez B. Roggisch wrote:

> George Sakkis schrieb:
> > Diez B. Roggisch wrote:
> >> Dr. Pastor schrieb:
> >>> 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.
> >>> (A pointer will point to the next byte to write to.)
> >>> What would be the Pythonic way to do the above?
> >>> Thanks for any guidance.
> >> Use a list, use append and slicing on it:
> >>
> >>
> >> max_size = 10
> >> buffer = []
> >>
> >> for i in xrange(100):
> >>      buffer.append(i)
> >>      buffer[:] = buffer[-max_size:]
> >>      print buffer
> >>
> >>
> >> Diez
> >
> > You're not serious about this, are you ?
>
> Tell me why I shouldn't. I presumed he's after a ringbuffer. Ok, the
> above lacks a way to determine the amount of bytes added since the last
> read. Add a counter if you want. And proper synchronization in case of a
> multithreaded environment. But as the OP was sketchy about what he
> actually needs, I thought that would at least give him a start.
>
> Maybe I grossly misunderstood his request. But I didn't see your better
> implementation so far. So - enlighten me.

Strange; there are two threads on this and my reply was sent to the
first one: http://tinyurl.com/lm2ho. In short, adding a new mark should
be a simple O(1) operation, not an O(buf_size). This is textbook
material, that's why I wasn't sure if you meant it.

George