Parallel(?) programming with python

[Oscar Benjamin]

On Mon, 8 Aug 2022 at 19:01, Andreas Croci <andrea.croci at gmx.de> wrote:
>
> tI would like to write a program, that reads from the network a fixed
> amount of bytes and appends them to a list. This should happen once a
> second.
>
> Another part of the program should take the list, as it has been filled
> so far, every 6 hours or so, and do some computations on the data (a FFT).
>
> Every so often (say once a week) the list should be saved to a file,
> shorthened in the front by so many items, and filled further with the
> data coming fom the network. After the first saving of the whole list,
> only the new part (the data that have come since the last saving) should
> be appended to the file. A timestamp is in the data, so it's easy to say
> what is new and what was already there.
>
> I'm not sure how to do this properly: can I write a part of a program
> that keeps doing its job (appending data to the list once every second)
> while another part computes something on the data of the same list,
> ignoring the new data being written?
>
> Basically the question boils down to wether it is possible to have parts
> of a program (could be functions) that keep doing their job while other
> parts do something else on the same data, and what is the best way to do
> this.

Why do these "parts of a program" need to be part of the *same*
program. I would write this as just two separate programs. One
collects the data and writes it to a file. The other periodically
reads the file and computes the DFT.

Note that a lot of the complexity discussed in other posts to do with
threads and locks etc comes from the supposed constraint that this
needs to be done with threads or something else that can work in
parallel *within the same program*. If you relax that constraint the
problem becomes a lot simpler.

--
Oscar