Register events and access the runned cell content

[theevann]

I would like to be able to register events on colab like in Jupyter, and then access the runned cell content using: IPython.get_ipython().events.register('post_run_cell', function)

• In Jupyter, post_run_cell is called with an argument (an ExecutionResult object) as you can see here, so its signature is post_run_cell(ExecutionResult result).
  But in colab, there is no argument given to post_run_cell. Should it be considered a bug ?

• I tried a workaround using the last_execution_result variable (also an ExecutionResult object), with IPython.get_ipython().last_execution_result but once again its seems to work in Jupyter only and I didn't find any equivalent. Is there any ?

In Jupyter, any of these two gives me an ExecutionResult object, from which I can get the cell raw input: result.info.raw_cell.

I finally found a workaround that would work only in colab :

import IPython
ip = IPython.get_ipython()
def f():
    cell_content = ip.get_parent()['content']['code']
ip.events.register('post_run_cell', f)

My questions : Are all these differences normal ? Is there a "cross-platform" way to do it ?

[blois]

I think the issue is the version of IPython that Colab is on right now. If I upgrade the kernel then it appears to work as you're expecting:
https://colab.research.google.com/gist/blois/057009f08ff1b4d6b7142a511a04dad1/post_run_cell.ipynb

[colaboratory-team]

Colab's IPython is currently on version 5.5 (version 6.0 dropped Python 3 support, and Colab still supports Python 2 kernels). If you're interested in using IPython events in IPython version 5.X, you can follow the documentation at https://ipython.readthedocs.io/en/5.x/config/callbacks.html.