[CIG-SHORT] Python debugging

[Brad Aagaard]

On 4/24/12 6:31 PM, Birendra jha wrote:
> Hi developers,
>
> 1. What is technique to debug both Python and C++ code together at
> runtime? When I uncomment start-in-debugger in pylithapp.cfg, it
> opens gdb window where I can debug c++ code. But what about debugging
> python code? Is there a different tool?

It is difficult. If you want debugging with both then you need to use 
the python debugger and then attach a gdb process. Usually, I limit 
myself to one or the other.

> 2. How do I print contents of a SwigPyObject array pointer?  The
> arrays returned by SWIG modules to Python are PyObjects. How to
> visualize them? Writing to a file will also work.

If the array is converted to a numpy array, then you can print from 
Python. If it is C++, there is no easy way to access it from python.

> 3. Implicit.py has a disp object. How do I visualize its content at
> runtime? print disp of course doesn't work and gives:
> <pylith.topology.topology.MeshField; proxy of<Swig Object of type
> 'pylith::topology::Field<  pylith::topology::Mesh>  *' at 0x2d9fba0>

Use the view("label") method to view the contents of meshes and sections 
(disp is a section).  The python dir(object) is very helpful to see what 
methods are accessible.

Brad