[Twisted-Python] Twisted and ipython

[Alessandro Dentella]

thanks Jean-Paul for the hints,

On Sun, Jan 16, 2011 at 12:50:05AM -0000, exarkun at twistedmatrix.com wrote:
> On 13 Jan, 11:43 pm, sandro at e-den.it wrote:
> >thanks,
> >
> >short abstact: manhole is very good, thanks. But I'd need to add 
> >readline to
> >make it usable and I'd need tab-completion too.
> 
> If by "add readline" you mean handle input using the stdlib readline 
> module, you can't really do this (or, I'm sure you can, but it would 
> involve a ton of coding).  If you only mean "have some commonly useful 
> line editing features" then you have at least a couple options:

Well, in fact I intended mainly up/down arrows *and* tab-completion, like
ipython have. 

>   * invective includes a fully unit-tested line input widget (for the 
> insults widget library).  This really belongs somewhere other than 
> invective, it'd be nice if someone pushed it back into Twisted. 
> However, you can find invective at 
> svn://svn.twistedmatrix.com/svn/Twisted/sandbox/exarkun/invective/trunk 
> until that happens.
> 
>   * urwid supports Twisted and has lots of fancy things, including an 
> input editing widget.

>From what you say I don't know if completion is something I'd
get with invective of urwid.

> Also, we really should get rid of twisted.manhole, because these days 
> manhole is supposed to refer to the stuff in twisted.conch.  I'm not 
> sure if you found the latter, but from the warning you got about 
> twisted.protocols.telnet it seems like you may have only found the 
> former.

I was able to use only manhole.telnet. I wan't able to understand how to
make twisted.protocols.telnet work in the same way and was not able to fine
a demo snippet (more for completeness that else I'm still interested in
this).

On the other hand I managed to use ipython and twisted as I wanted and
everitying is working like a charm (but I still have a question that I'll
leave for next chapter).

Twisted in a thread - working setup
-----------------------------------

Following a hint in the ipython ml I started a second thread for twisted and
I'm using blockingcallFromThread to dispatch commands to the reactor:

    proto = Domotik()
    SerialPort(proto, o.opts['device'], reactor, baudrate=int(o.opts['baudrate']))

    rit = twistedutil.ReactorInThread()
    rit.setDaemon(True)
    rit.start()

    q = Quadro(proto, discover=False)
    proto.quadro = q
    q.discover_modules()

This works exactly as I wanted. I can interact with 'q' that represents a
collection of electric modules on the serial bus 


The unresolved doubt
--------------------------------

What I can't understand is why I can't put "q.discover_modules()" inside
callWhenRunning() command: if I do that it just blocks at the first
iteration of the 'for' loop.

    reactor.callWhenRunning( start_command, proto)

    def start_command(proto):
	q.discover_modules()

    class Quadro(object):

	def __init__(self, proto):
	    self.proto = proto
	    self.modules = []

	def discover_modules(self):
            """send a request to the serial bus to understand which electric
            modules are present"""

	    for x in range(10):
		blockingCallFromThread(reactor.callLater, 1 + x/5.0, self.proto.ask_status, x)


thanks

sandro
*:-)


-- 
Sandro Dentella  *:-)
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