[IPython-dev] Argument parsing (was: Qt api selection re. ipython and matplotlib)

[Darren Dale]

On Wed, Jul 6, 2011 at 2:19 AM, Brian Granger <ellisonbg at gmail.com> wrote:
> On Tue, Jul 5, 2011 at 11:06 PM, MinRK <benjaminrk at gmail.com> wrote:
>> On Jul 5, 2011, at 18:32, Darren Dale <dsdale24 at gmail.com> wrote:
>>> By the way, I find the new ipython's new argument parsing really
>>> non-intuitive. It took me 5 attempts to figure out how to do "ipython
>>> gui=qt", even after skimming the output of "ipython -h". What's wrong
>>> with "ipython --gui=qt"? Does ipython really need to put its own
>>> unique spin on argument parsing?
>>
>> The reason for Brian's design here is that now the command line args
>> are coupled with the config system.  Specifying a value on the command
>> line is now identical to specifying it in a config file, so it looks
>> like a Python assignment (because it is).  It also means that 100% of
>> IPython is configurable from the command-line.
>
> As Min mentions, the config system syntax *is* Python and we wanted to
> use a syntax that reflected that.  When you do:
>
> Foo.bar=10
>
> At the command line, we parse that as Python code and run it through
> the traits machinery.  Making this:
>
> --Foo.bar=10
>
> Only obscures the fact that it is parsed as Python.

That's a bit hyperbolic. I could then argue that "ipython profile
create" only makes it confusing to figure out what arguments should be
treated as options and what arguments should be treated as files.

> This approach
> also allows us to do things like the following at the command line:
>
> Foo.bar=[0,1,2]
>
> or even:
>
> Foo.bar=range(3)
>
> Which is then validated by traits as a list of ints.  We do realize
> that there is going to be an adjustment period for users and we do
> need to continue to improve documentation to point out these important
> changes.

Could you please include some documentation on how I can invoke
ipython to run a script without a .py or .ipy extension? Lets say I
have a python script called "profile", this doesn't work:

ipython profile

Or, suppose I have a file named something pathological like foo=bar?
Python will run it without any problems. Even if I rename it
foo=bar.py, ipython appears to interpret it as an option, not a
filename.

Darren