[IPython-dev] slow startup due to script magic

[Thomas Kluyver]

On 22 September 2012 06:26, Jason Grout <jason-sage at creativetrax.com> wrote:
> We eventually traced it down to the loading of the
> script extension, which by default does 6 popen calls to find the paths
> of scripts in the _script_magics_default method, which are really slow
> (something like 200 ms for the calls on my computer):

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.

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.

Thomas