How to display mel error in Python ?

[Chadrik]

pymel (http://code.google.com/p/pymel/) supports this. it will return different types of exceptions depending on what type of mel error occurs, along with the full error message and line numbers. docs on the subject are here (http://pymel.googlecode.com/svn/docs/generated/classes/pymel.core.language/pymel.core.language.Mel.html#pymel.Mel).

sourcing your script in pymel looks like this:
mel.source("script.mel")

[Ourouk]

Thanks...

But I would like to avoid using another "extra package" like PyMel. I already use PyQt and installing it on various OS in various company is complicated (write permissions, as many install as os, os version etc etc). In fact, with PyQt i can't always use my tools... :/
But I can do UI in mel no more ;)

If I had another package, it'll be twice as complicated ;)

So ? Is there any other solution in pure Python ?

thanks

[CaptainSam]

PyMel really is THE big Maya Python project. If your serious about Maya scripting, there is basically no way around it, unless you love reinventing the wheel all the time.

[Ourouk]

Yeah I know that pyMel rocks ;)
Perhaps I'll give it a try...In fact it is already unpacking ;)

But by the way, is there any solution for now for my problem ? :)

[Chadrik]

Check out the code in the Mel class in pymel.core.language. it uses MCommandResult to handle the calling of mel scripts so that it can retrieve error messages. if you don't want to use pymel you can use this code on your own, but there's no standard way to do this without making a utility like the Mel class. like CaptainSam said, if you're not using pymel you're either not using python in maya to its fullest or you're reinventing the wheel.

-chad

[Ourouk]

Reinventing the wheel as always been my biggest dream ;)

thanks for the info...Will try asap ;)
bye

[Ourouk]

Ok...I installed pymel, with some problems...

Auto install error message :
Unexpected token 'setup.py' in expression or statement.
At line:1 char:53
+ "e:\softs\maya2009\bin\mayapy.exe" setup.py <<< install

So I switch to manual install which worked...but what is the problem with auto install ?

thanks
bye

[Chadrik]

you got that from a windows shell? that doesn't look like a windows shell error....

[Ourouk]

Yep it was a window shell...but not the default shell, it's windows powershell.
will try with the default one.

[underearth]

i use following to display error (maya command error)

import maya.mel as mm
try:
mm.eval('error "there is error";')
except RuntimeError:
pass

[Chadrik]

in your example, you cannot programmatically retrieve the error message in python:

import maya.mel as mm
try:
mm.eval('error "there is error";')
except RuntimeError, err:
print str(err)

from python this prints 'Error occurred during execution of MEL script' and not the desired 'there is error'.

the same problem exists for errors that happen inside mel that are unintended, like syntax errors, conversion errors, etc.

[Ourouk]

Hi I think I have a pretty crappy solution but...while I am trying pymel, it'll be this way ;)
(thanx to kelsolaar and gaviez)

so all I had to do was this :

import maya.mel as mel
try:
mel.eval("source \"myscript.mel\";myscript();")
except:
pass

it just display the good error message given by the mel script :

// Error: select at least 1 mesh to optimize

For now it is a temporary solution...but it works...don't need more...

thanks !

[underearth]

at workplace where i am using maya Python i'm also using same way for error..
but at my personal projects I JUST LOVE PYMEL... ( i wish it could have been maya's default)

thanks once again chad

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