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

[Martin Braun]

Current GRC on master allows you to type Python code directly into the
flow graph to be executed as a block. Simply insert a 'Python block'.

M

On 03/16/2016 02:34 PM, Dennis Glatting wrote:
> 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.
>>>
>>>
>>>
>>>
>>>  
>>>
>>>
>>> _______________________________________________
>>> Discuss-gnuradio mailing list
>>> address@hidden
>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>>
> 
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