Rendering HTML/Javascript in IPython/Jupyter Notebook from a thread

Question

I want to use IPython notebook's IPython.display.display from within a thread, as such:

def foo():
    display(HTML('<div id="foobar">foobarbaz</div>'))
threading.Thread(target=foo).start()

IPython notebook spits out the following error:

Exception in thread Thread-17:
Traceback (most recent call last):
  File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.5/threading.py", line 862, in run
    self._target(*self._args, **self._kwargs)
  File "<ipython-input-47-921e56bac735>", line 2, in foo
    display(HTML('<div id="foobar">foobarbaz</div>'))
  File "/usr/local/lib/python3.5/dist-packages/IPython/core/display.py", line 171, in display
    publish_display_data(data=format_dict, metadata=md_dict)
  File "/usr/local/lib/python3.5/dist-packages/IPython/core/display.py", line 121, in publish_display_data
    metadata=metadata,
  File "/usr/local/lib/python3.5/dist-packages/ipykernel/zmqshell.py", line 111, in publish
    for hook in self.thread_local.hooks:
AttributeError: '_thread._local' object has no attribute 'hooks'

I figure IPython's display is not thread safe? Is there a way to get it to point to the main thread instead of the local thread? Or perhaps a way to get the IPython.display.DisplayHandle ? Maybe the thing to do is to have a loop around a queue.Queue on the main thread and display objects as they get added into that queue?

Thank you!

Answer 1

You can use an Output widget to display your HTML. This worked for me:

import ipywidgets as widgets
from IPython.display import display, HTML
import threading

out = widgets.Output()

def foo():
    with out:
        display(HTML('<div id="foobar">foobarbaz</div>'))

threading.Thread(target=foo).start()

out