Re: [gentoo-user] new machine : suddenly Python 3 appears

[Marc Joliet]

Am Thu, 20 Sep 2012 13:38:45 +0200
schrieb Willie WY Wong <wongwwy@××××××××××.org>:

> On Wed, Sep 19, 2012 at 09:08:52AM +0200, Penguin Lover Marc Joliet squawked:
> > 2.) The full blown interactive solution: IPython. You can create a session and
> > configure which modules you want preloaded via startup scripts. This is
> > overkill for what you want, I think, but IPython is a much nicer interactive
> > Python interpreter than python itself. For instance, you can reuse previous
> > outputs, e.g. "Out[2]", to get the output from the third command you entered
> > (indexing starts at 0). Inputs can be similarly recalled by referencing
> > "In[i]".
>
> Yes, I recommend ipython too.
>
> > 3.) Put the "import" line in its own file and put it in the variable
> > PYTHONSTARTUP, e.g. "export PYTHONSTARTUP=/path/to/my/script.py". Python
> > executes it's contents before presenting the prompt, so you can put whatever
> > imports you want in that script. It's simple, and if the python interpreter is
> > enough for you, then I'd go with this.
> >
> > There are probably more possibilities, but this is what I can think of right
> > now.
>
> Unless you want to load the math module every single time you start
> Python, it is perhaps better to create an alias (say, python-calc)
> in bash (or shell of your choice) using the `-i' option of python
> like
>   alias python-calc='python -i loadmath.py'
> or if you only need one single command
>   alias python-calc='python -i -c "from math import *"'
> which will give you an interactive session with the math functions
> preloaded.

You are right, exporting PYTHONSTARTUP globally for something like this
in the bashrc would in this case be stupid, or at least wasteful. I like your
alias version better :) .

> Cheers,
>
> W

Greetings
-- 
Marc Joliet
--
"People who think they know everything really annoy those of us who know we
don't" - Bjarne Stroustrup