Generate variables at run time?

[Byron Morgan]

Thanks, Mike, and all who responded -

The dictionary is probably the way to go - I'll try some of the other
suggestions too. I had hesitated to take up environment space with 175
predefined variables, given my dictionaries already comprise over 1500
entries, almost 53K.

Now, I have to tackle learning OOP python style, as well as threading. My
app will be an event monitor, sending pages, instant messages, cellular text
messages, etc., based on various triggering events.


"Mike Meyer" <mwm at mired.org> wrote in message
news:x7bs2quwt6.fsf at guru.mired.org...
> "Byron Morgan" <lazypointer at yahoo.com> writes:
>
> > I have been using REXX for years for all my scripting needs. In REXX, I
can
> > use any string as a variable with no special handling.
>
> I coded Rexx for years as well. Python isn't Rexx, so you'll need to
> do things a different way.
>
> > Here is the project:
> >
> > A server supplies an alphanumeric data stream over an internet socket.
The
> > data is output from a train control system. Trains constantly enter and
> > leave the controlled territory, and each has a unique ID. I want to use
a
> > class named  "train", and name each new instance based on this ID. For
> > example, train 123 will cause creation of  T123=train(). While the train
is
> > in the system, it will be frequently updated based on new data, then it
will
> > be destroyed when the train leaves the system.
> >
> > for the curious:
> > In REXX, for a similar situation, I use a stem "train", then add the
train
> > number, then add each attribute as events are reported.
> > train. = 0
> > train.123 = 1 (value represents the number of cars in train)
> > train.123.stat = 1 (0 if stopped, 1 if moving)
> > train.123.doors = 1 (1 if closed, 0 if open)
>
> The closest things to stemmed variables is a dictionary. In fact,
> they're almost the same thing, just with different syntax.
>
> Assuming you have a class Train, here's how to
>
> Create the list of trains: train = {}
> Create a new train: train[123] = Train()
> Set the status: train[123].stat = 1
> Read the status: train[123].stat
>
> Close the door on all stopped trains:
> for t in train.values():
>     if t.stat: t.door = 1
>
> Get a list of the names of all stopped trains:
>     [x for x in train.keys() if train[x].stat]
>         # Note: in recent pythons, "train.keys()" can be replaced by just
"train"
>
> While I miss the easy access to applications, I generally find that
> programming in python is much more pleasant than programming in Rexx.
>
>         <mike
> --
> Mike Meyer <mwm at mired.org> http://www.mired.org/home/mwm/
> Independent WWW/Perforce/FreeBSD/Unix consultant, email for more
information.