[IPython-dev] slow startup due to script magic

Fernando Perez fperez.net at gmail.com
Sat Sep 22 14:33:10 EDT 2012

On Sat, Sep 22, 2012 at 3:40 AM, Thomas Kluyver <takowl at gmail.com> wrote:
> Hmm, well spotted. If it's that slow, I think we should avoid doing it
> during IPython start up at all. I like it to start up quickly.

Absolutely, thanks for catching this, Jason!  Indeed, startup time is
a really important consideration, and we should be very careful with

Does anyone have a tool to instrument the startup process in an easy
manner?  Jason, if you guys have any such tools for Sage that you
could share, we could track these things and prevent similar
regressions in the future.

> Maybe we should keep it simple: rather than checking for the existence
> of each interpreter, just set a standard list. It would mean that
> users can tab complete e.g. %%pypy, even if they don't have pypy
> installed, but I don't think it will be too surprising if they try it
> and it fails.

We could also cache the search path and do it only on first usage,
rather than at IPython startup.  Else we can discuss moving this to an
optional extension...



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