[Bf-python] blender and external editors - workflow?

[Marc Weber]

Excerpts from Marc Weber's message of Fri Aug 20 14:30:08 +0200 2010:
> Excerpts from Marc Weber's message of Fri Aug 20 09:20:20 +0200 2010:
> >   File "/home/marc/mwr/vim-addon-blender-scripting/blender_server.py", line 59, in blenderServer
> >     sys.exit(1)
> > SystemExit: 1
> 
> This was caused by a sys.exit() call I forgot to remove. So not using a
> background thread works fine now.
> Don't ask me why it popped up whenever you typed *any* line.
> Maybe the error is not cleared by blender if was caused in a thread (?)
> 
> 
> What could be the reason that context.scene has type NoType?
> 
> I tracked it down:
> after s.accept
> context.scene (which was imported by  from bpy import context) is gone
> 
>     print("in thread 2 "+str(type(context.scene)))
>     try:
>       # receive requests loop:
>       while True:
>         conn, addr = s.accept()
>         print("in thread 3 "+str(type(context.scene)))
> 
> Everything is working fine but this small detail?
> 
> scene is only set to NoneType if s.socket is called in a thread

Adding this loop to script running it within a Python thread shows that
the scene stat changes from scene object to NonType after 1389
iterations.

      while True:
        print(str(type(context.scene))+str(n))
        n = n +1

It also makes blender segfault.


Also adding a timer shows that the scene is present sometimes and
sometimes not:

    t = timeit.Timer()
    try:
      n = 1
      while True:
        print(str(type(context.scene))+str(n),"  ",t.timeit())
        n = n +1


first number is iteration step, the second is timing.

  <class 'bpy.types.Scene'>1    0.0226609706879
  <class 'NoneType'>2    0.0202839374542
  <class 'NoneType'>74    0.0213420391083
  <class 'bpy.types.Scene'>75    0.0255241394043
  <class 'bpy.types.Scene'>78    0.0206708908081
  <class 'NoneType'>79    0.0207800865173
  <class 'NoneType'>2548    0.029464006424
  <class 'bpy.types.Scene'>2549    0.0397069454193
  <class 'bpy.types.Scene'>2551    0.0279560089111
  <class 'NoneType'>2552    0.0205199718475


So is scene only attached when a python script is evaluated?

Marc Weber