Stripping other metadata (execute time)

[jdriordan]

I'm using the (hugely useful) Execute Time nbextension, which produces cell metadata like this:

{
 "cell_type": "code",
 "execution_count": null,
 "metadata": {
  "ExecuteTime": {
   "end_time": "2016-08-15T11:49:40.736068",
   "start_time": "2016-08-15T11:49:40.145965"
  },
  "code_folding": [],
  "collapsed": false
 },
 "outputs": [],
 "source": []
}

But naturally I end up with a load of changes seen by git after running nbstripout because of re-running the cells and updating the ExecuteTime field. Would you accept a pull request explicitly stripping this out, or alternatively one which strips all but whitelisted metadata entries?

[kynan]

I suppose stripping all but whitelisted metadata would make sense. How do you envision configuring that whitelist?

[kynan]

@jdriordan, are you still planning to submit a pr for this?

[jdriordan]

Sorry for the delay. One way to do a whitelist would be to start with those given in the format spec, i.e.

• kernelspec
• collapsed
• autoscroll
• deletable
• format
• name
• tags
• isolated

along with those used by nbstripout,

• init_cell
• keep_output
• scrolled

People seem to be using metadata for other various things in the wild (author/description etc.) and it's also used by some extensions (which could register themselves on the whitelist, in theory).

Having looked at all this I've managed to convince myself a blacklist is a more sensible option (since other metadata doesn't change in a useless way like this does. So I've ended up making a really simple change that just strips this one field (but could trivially do others too).

PR submitted.

[kynan]

I agree with your rationale about blacklisting rather than whitelisting. PR merged!

[michaelaye]

time to release maybe? ;)

[kynan]

@michaelaye This is actually already released in 0.2.9