Exploratory query

[Alex Martelli]

Don Todd wrote:

> I'm a total python newbie and have not really even begun to learn.
> Before I start, however, I would like to know if python is the proper
> tool for what I want to do.
> 
> I want to query various MH mailboxes to see if they contain new mail.
> There is a program, flist, that will do this, but it is a pain to run it
> every time. I'd like something a la xbiff or gbiffy.
> 
> Would python allow me to run flist and use its output, or would I need
> to re-write flist? The idea is to keep something on the screen and poll
> the mailboxes every n seconds and update the display.

Yes, it should be pretty easy to write a Python script (with e.g. a
Tkinter GUI) to do just this -- run another arbitrary program X every
Y seconds and keep a window display with the latest stdout of said
program X.  (Of course, you can then make a more refined version that
knows the format of stdout for given programs and parses it in order
to provide prettier or more useful output, and add more features).

Such a script could be something like:

import Tkinter as Tk
import optparse, sys, os

# acquire arguments
parser = optparse.OptionParser()
parser.add_option('-c', '--command', dest='command',
    help='Command to be executed periodically',
    metavar='PIPELINE', default='date')
parser.add_option('-p', '--period', dest='period',
    help='How many seconds to wait between executions',
    metavar='SECONDS', default=5)
options, args = parser.parse_args()
if args:
    print >> sys.stderr, "Unknown args %r ignored" % args

# run command, update output if needed
last_output = ''
def run_command():
    global last_output
    new_output = os.popen(options.command).read()
    if new_output != last_output:
        last_output = new_output
        text.config(state=Tk.NORMAL)
        text.delete(1.0, Tk.END)
        text.insert(Tk.END, new_output)
        text.config(state=Tk.DISABLED)
    text.after(options.period, run_command)
    
# prepare and display a GUI
text = Tk.Text()
text.config(state=Tk.DISABLED)
text.pack()
run_command()
Tk.mainloop()


Running this with -cflist should already give you a first rough
prototype of what you might want.  Many improvements are of course
possible, but I hope this shows it's worth studying some Python
(and Tkinter, or other GUI toolkit if you prefer) in order to be
able to implement such improvements.


Alex