matplotlib-devel Mailing List for matplotlib

Abraham Schneider wrote:
> I completely agree. I recently changed the code to allow a path to be 
> specified (':' deliminated). I hadn't thought of allowing '$VAR' syntax 
> .. something to think about. However, if people have a .matplotlibrc 
> file in their home directory, it should make it so people aren't mucking 
> up things with the plugins.. I'll have to check the behavior of 
> find_module to see what it does with '~' and such.

You can expand the user-given string by doing:

user_dirlist = os.path.expanduser(os.path.expandvars(user_path)).split(':')

This gives you a list of directories to search, with user ~names and 
$VARIABLES expanded out.  This approach worked fine for mayavi.

Best,

f

Abraham Schneider wrote:
> I do like the idea, and I was actually going to suggest something 
> similiar earlier on, but thought it wise at the time not to rock the 
> boat too much.. I am currently using this technique for my own code and 
> it's working out extremely well. The biggest problem with this approach, 
> is that I'm guessing the average user doesn't want to trawl through 
> python code to change a setting, or worry why Matplotlib doesn't work 
> because of some strange error message.
> 
> Because of this, I think it might make the most sense to partition the 
> rc file. For common settings, keep the current RC format, but then allow 
> python code to be executed for other settings.
> 
> A simple approach for this might be to add in directives to the RC 
> language like:
> 
> @import('file.rc')
> 
> or
> 
> @import('file.py')
> 
> Depending on the file type (i.e. ends in 'rc' or ends in 'py'), the file 
> could be parsed properly (either executed with 'execfile' with a given 
> namespace, or operate on rcParams).

-1, too complicated to code and maintain, IMHO.  And @foo looks poised to 
become valid python syntax, in case you've missed the recent firestorms on 
c.l.py and python-dev.

In my view, matplotlib (and similarly ipython) are already tools for people 
coding in python to begin with.  So they can deal with python syntax, 
otherwise they wouldn't be using them.  Simplified syntaxes may make sense for 
configuring end-user programs, but for that we already have ConfigParser in 
the stdlib.  We have better things to do than reinventing half-working 
implementations of toy languages, and users will always end up needing an if 
statement, a looping construct, a system access function, etc.  Might as well 
just give them all of python and be done with it, I think.

The approach I have in mind for ipython is simply making sure that any 
exceptions generated during the execution of this file are presented very 
clearly to the user, with full source details and a clear message wrapping 
them going to stderr.  This will indicate not only the exception but the fact 
that it is occurring in the user's config file and that ipython (or 
matplotlib) can't proceed further until this is fixed.  IPython comes with a 
better exception formatter than the default (ultraTB, essentially a console 
port of cgitb); matplotlib is welcome to use it.

Best,

f

John Hunter wrote:
>>>>>>"Fernando" == Fernando Perez <Fer...@co...> writes:
> 
> 
>     Fernando> 2. From some of your syntax struggles, I'm starting to
>     Fernando> wonder whether it would be best to turn the
>     Fernando> .matplotlibrc file into a proper python one.  I followed
>     Fernando> the same approach with ipython of having a custom
>     Fernando> syntax, and now I regret it. It appears easier
>     Fernando> initially, but in the long term it's clunky (at least
>     Fernando> for ipython).  For ipython's next major revision, I plan
>     Fernando> on dumping its own rc format and allowing users to
>     Fernando> define their configuration using plain python syntax.
>     Fernando> Just some thoughts.
> 
> I had the same thought this morning - you start with a simple config
> file, key/value pairs, but as you add features you find yourself
> writing a little primitive mini-language.  Why ham-string yourself,
> when you already have an elegant, simple, powerful language available
> - python!

There are a few technical issues with this problem, some of which I've partly 
thought about.  This will be one of my first things to do once I'm done with 
matplotlib support in ipython, as part of the rewrite.  Perhaps we could share 
some of the work for this problem with a light module for handling python 
config files with proper namespace control and recursive inclusion (important 
for handling global defaults modified by local project fine-tuning).

Best,

f

Fernando Perez wrote:

>
>
> 1. I think plugin support is a fantastic idea, but I hope it can be 
> made user-extensible in local paths.  I recently modified mayavi 
> (available in current CVS) precisely in this manner, and I think it's 
> a very useful thing. In lab settings where users are not allowed to 
> write to system directories, it becomes very important that they can 
> add their own plugins in local paths. This also allows you to keep 
> your personal extensions alive as matplotlib versions are upgraded, 
> since your directories are untouched.
>
> What I did for mayavi was to add a search-path option to mayavi, made 
> of colon-separated dirs with ~user/$VAR support.  Any such dir gets 
> added to mayavi's search path for user-defined filters and modules 
> (the equivalent of plugins), and you can load a user module just like 
> you can load a builtin:
>
> load_module('Glyphs') -> loads mayavi's Glyphs module
> load_module('User.Glyphs') -> loads a user-defined Glyphs module from 
> the search path.
>
> I think it's important that it's a _path_ and not a single directory, 
> because this allows a research group to maintain shared extensions 
> suited for their purposes, and individual users to add personal 
> modifications which don't fit group projects.

I completely agree. I recently changed the code to allow a path to be 
specified (':' deliminated). I hadn't thought of allowing '$VAR' syntax 
.. something to think about. However, if people have a .matplotlibrc 
file in their home directory, it should make it so people aren't mucking 
up things with the plugins.. I'll have to check the behavior of 
find_module to see what it does with '~' and such.

I like the idea of 'load_module'. Currently all the plugins in the 
directories are loaded automatically. There is a certain nicety, though, 
to automatically having it load all the plugins found in a particular 
directory. Less cumbersome for most users.

Abe

I do like the idea, and I was actually going to suggest something 
similiar earlier on, but thought it wise at the time not to rock the 
boat too much.. I am currently using this technique for my own code and 
it's working out extremely well. The biggest problem with this approach, 
is that I'm guessing the average user doesn't want to trawl through 
python code to change a setting, or worry why Matplotlib doesn't work 
because of some strange error message.

Because of this, I think it might make the most sense to partition the 
rc file. For common settings, keep the current RC format, but then allow 
python code to be executed for other settings.

A simple approach for this might be to add in directives to the RC 
language like:

@import('file.rc')

or

@import('file.py')

Depending on the file type (i.e. ends in 'rc' or ends in 'py'), the file 
could be parsed properly (either executed with 'execfile' with a given 
namespace, or operate on rcParams).

This could also support other features such as verbosity:

@verbose moderate

That said, I think the current syntax for adding widgets and connecting 
them isn't too bad. I think it's worth experimenting with to see which 
is easier to use.

Abe

John Hunter wrote:

>>>>>>"Fernando" == Fernando Perez <Fer...@co...> writes:
>>>>>>            
>>>>>>
>
>    Fernando> 2. From some of your syntax struggles, I'm starting to
>    Fernando> wonder whether it would be best to turn the
>    Fernando> .matplotlibrc file into a proper python one.  I followed
>    Fernando> the same approach with ipython of having a custom
>    Fernando> syntax, and now I regret it. It appears easier
>    Fernando> initially, but in the long term it's clunky (at least
>    Fernando> for ipython).  For ipython's next major revision, I plan
>    Fernando> on dumping its own rc format and allowing users to
>    Fernando> define their configuration using plain python syntax.
>    Fernando> Just some thoughts.
>
>I had the same thought this morning - you start with a simple config
>file, key/value pairs, but as you add features you find yourself
>writing a little primitive mini-language.  Why ham-string yourself,
>when you already have an elegant, simple, powerful language available
>- python!
>
>When I get some more time tomorrow I'll take a close look at Abraham's
>code, and whether it might make more sense to move this section, or
>the who rc file, into python.  That Abraham was able to factor out /
>modularize most of the toolbar code will certainly pave the way.
>
>Abraham, had you given this approach any thought in the midst of your
>work?
>
>Thanks!
>JDH
>
>
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>>>>> "Fernando" == Fernando Perez <Fer...@co...> writes:

    Fernando> 2. From some of your syntax struggles, I'm starting to
    Fernando> wonder whether it would be best to turn the
    Fernando> .matplotlibrc file into a proper python one.  I followed
    Fernando> the same approach with ipython of having a custom
    Fernando> syntax, and now I regret it. It appears easier
    Fernando> initially, but in the long term it's clunky (at least
    Fernando> for ipython).  For ipython's next major revision, I plan
    Fernando> on dumping its own rc format and allowing users to
    Fernando> define their configuration using plain python syntax.
    Fernando> Just some thoughts.

I had the same thought this morning - you start with a simple config
file, key/value pairs, but as you add features you find yourself
writing a little primitive mini-language.  Why ham-string yourself,
when you already have an elegant, simple, powerful language available
- python!

When I get some more time tomorrow I'll take a close look at Abraham's
code, and whether it might make more sense to move this section, or
the who rc file, into python.  That Abraham was able to factor out /
modularize most of the toolbar code will certainly pave the way.

Abraham, had you given this approach any thought in the midst of your
work?

Thanks!
JDH