Ocassionally getting "AttributeError: 'NoneType' object has no attribute 'x' " after some ticks

[Alex98156]

Hi, me again
In order to build and run a simulation based on walk example, i get the title problem (sometimes not). Something to stand out is that more cores i use, more faster the message appears (tested 1, 2,...5 cores) i believe it's some coordinates conflict or something with some code that i've made (outside abm structure) trying to randomize agent spawn to not depending always on the same seed (code below) and performing a more randomized behaviour in agent move and spawn.

Seed code:

#RANDOM SEED
random_seed = os.urandom(1)
random_fin = int.from_bytes(random_seed,byteorder="little")


with open('mainFinal.yaml') as f:
    data = yaml.safe_load(f)
    valores = data['random.seed']
    
    if data['random.seed'] == 8:
        data['random.seed'] = random_fin

    else:
        data['random.seed'] = 8

    #Guarda el archivo .yaml
    with open("mainFinal.yaml", "w") as out:

        yaml.dump(data, out)

Note. If i pull out that code i get:

Traceback (most recent call last):
  File "mainFinal.py", line 282, in <module>
    run(params)
  File "mainFinal.py", line 275, in run
    model.start()
  File "mainFinal.py", line 269, in start
    self.runner.execute()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 258, in execute
    self.schedule.execute()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 161, in execute
    evt()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 32, in __call__
    self.evt()
  File "mainFinal.py", line 242, in step
    roedor.walk()
  File "mainFinal.py", line 99, in walk
    print(pt.coordinates)
AttributeError: 'NoneType' object has no attribute 'coordinates'
Traceback (most recent call last):
  File "mainFinal.py", line 282, in <module>
    run(params)
  File "mainFinal.py", line 275, in run
    model.start()
  File "mainFinal.py", line 269, in start
    self.runner.execute()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 258, in execute
    self.schedule.execute()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 161, in execute
    evt()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 32, in __call__
    self.evt()
  File "mainFinal.py", line 242, in step
    roedor.walk()
  File "mainFinal.py", line 99, in walk
    print(pt.coordinates)
AttributeError: 'NoneType' object has no attribute 'coordinates'

Error NoneType example on tick 29 of 30

Traceback (most recent call last):
  File "mainFinal.py", line 282, in <module>
    run(params)
  File "mainFinal.py", line 275, in run
    model.start()
  File "mainFinal.py", line 269, in start
    self.runner.execute()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 258, in execute
    self.schedule.execute()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 161, in execute
    evt()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/schedule.py", line 32, in __call__
    self.evt()
  File "mainFinal.py", line 238, in step
    self.context.synchronize(restaurar_agente)
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/context.py", line 294, in synchronize
    self._synch_ghosts(restore_agent)
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/context.py", line 258, in _synch_ghosts
    proj._synch_ghosts(self._agent_manager, restore_agent)
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/space.py", line 414, in _synch_ghosts
    send_data = self._fill_send_data()
  File "/home/usuario/.local/lib/python3.8/site-packages/repast4py/space.py", line 378, in _fill_send_data
    data_list.append((a.save(), (pt.x, pt.y, pt.z)))
AttributeError: 'NoneType' object has no attribute 'x'

Sorry for the long message and thanks for your time.
Alex

[ncollier]

I think the issue is that new agents are being created without their pt attribute being initialized. So, when pt is accessed it's None.

[Alex98156]

Hi, pt was pt = model.grid.get_location(self) but
i've found that actually pt wasn't changing since i've changed
self.grid = space.SharedGrid(name='grid', bounds=box, borders=space.BorderType.Sticky, occupancy=space.OccupancyType.Single, buffer_size=1, comm=comm)
from

self.grid = space.SharedGrid(name='grid', bounds=box, borders=space.BorderType.Sticky, occupancy=space.OccupancyType.Multiple, buffer_size=1, comm=comm)
now everything's fine, thank you very much.