Re: [Discuss-gnuradio] How to create a python block

[Dennis Glatting]

On Wed, 2016-03-16 at 16:58 -0400, James Humphries wrote:
> Hi Dennis,
> 
> Have you seen these:
> 
> https://gnuradio.org/doc/doxygen/page_python_blocks.html
> 
> and
> 
> http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorial_GN
> U_Radio_in_Python
> 
> They have some good info on how to setup your Python block.
> 

This is where I am confused, not being a Python hack. I didn't want to
create the graph by connecting things together in a python script, such
as:

src = blocks.vector_source_f (src_data)
mult = multiply_py_ff (2)
snk = blocks.vector_sink_f ()self.tb.connect (src, mult)
self.tb.connect (mult, snk)

Rather I wanted the python block to be part of the GUI run graph.
Specifically, my graph looks like this:


Rx -> Demod C++ ------> MITM ---> Mod C++ -> Tx
^       ^               ^  ^        ^        ^
|       |               |  |        |        |
--------|               |  |        |        |
Controls                |  |        |        |
                        |  |        |        |
Fixed extensions--------|  |        |        |
Python extensions ---------|        |        |
                                    |        |
Controls ---------------------------|--------|

My thinking is within the properties field of a block a person could
type some python code where the block imports the code and runs it.
Sounds like that isn't the workable approach? (The MITM block has
canned messages and fixed manipulations based on GUI controls, which is
fairly limiting as a penetration test tool.)

When I looked at some examples I saw either C++ blocks or Python blocks
but the python code created the whole graph itself.

I think what you are telling me (and looking through the web pages) is
I could have an ugly, fixed C++ MITM block /and/ a separate python
block (i.e., two MITM blocks) with the python block part of the build,
or both could be incorporated into the python block for a better
design. Yes?

Sorry, I'm not a python hack so it isn't evident to me.

TIA.


> -Trip
> 
> On Wed, Mar 16, 2016 at 4:51 PM, Dennis Glatting <address@hidden>
> wrote:
> > This is probably a dumb question but someone has to ask them...
> > 
> > 
> > I have a run graph with c++ blocks: a receiver block, a transmitter
> > block, and a manipulator block. I want to have the manipulator
> > block
> > editable from the run graph where the user can insert python code.
> > Specifically:
> > 
> > 1) The block has two message ports: an "in" port and an "out" port.
> > 
> > 2) A user can write and type python code into the block to
> > manipulate
> > the message received on the input port and post the manipulated
> > message
> > on the output port.
> > 
> > 3) The python code may have to call other functions, such as
> > updating a
> > hash code.
> > 
> > How might I do that? I could do a c++ wrap around exec() but I
> > believe
> > there has to be an easier way since GNURadio is a combination of
> > python
> > and c++.
> > 
> > The incoming messages arrive at a low frequency and a low data rate
> > so
> > I'm not really concerned about processing time.
> > 
> > 
> > 
> > 
> >  
> > 
> > 
> > _______________________________________________
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> > address@hidden
> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >