[Tutor] is this doable

[Cameron Simpson]

On 31May2019 19:41, nathan tech <nathan-tech at hotmail.com> wrote:
>Is it possible, in python, to store a running task id in the registry?
>
>I might be using the complete wrong terms here, because I'm only used to
>doing this with a specific language, but here's what I want to do:
>
>python mytest.py:
>if(registry.taskid==valid_task):
>  print 'already open'
>  send to open program to make a ding noise.
>
>I understand that the second part, the "send to program" requires the
>program to handle being sent a "wake up!" event, which is fine, it's the
>"is it already running" which I am not sure on.

Well, you need to have some kind of persistent storage of tasks and a 
way to check if some described task is running.  I don't know what 
constitutes a task in your mind here, or what you consider "the 
registry".

There is any number of ways to store persistent values.

A simple one is a CSV file: keep one around with a line per task 
including the taskid and whatever other relevant information is needed.  
Reread the file when needed. To avoid difficulties with updating an 
arbitrary record in such a file (which is just a text file with lines of 
variying lengths) you could treat it like a log: just append more lines 
containing the new task state. On reading the file, just keep the last 
line per task.

Less simple, but more flexible, might be some kind of database. Python 
ships with SQLite3 support, which lets you have a little SQL database in 
a local file.

It is hard to be any more specific without knowing what you consider a 
task, and how you'd check if it was active.

Cheers,
Cameron Simpson <cs at cskk.id.au>