Handling Exceptions in Rhino's Editor

[frankfralick]

This may be a broader IronPython question. I need to code a variety of custom exceptions that have helpful messages. In the past with CPython I have made a class hierarchy of exceptions, so that I can test many conditions it a try statement, and then catch any of them using the superclass exception. Like this:

class SuperError(Exception):
    pass
class SubError(SuperError):
    def __init__(self,x):
        self.x = x
    def __str__(self):
        return repr(str(self.x)+" is not less than three.")
x = 4
try:
    if x > 3:
        raise SubError(x)
except SuperError as Y:
    raise Y

A standard CPython interpreter would create a Traceback that looks like this:

Traceback (most recent call last):
  File "C:\Projects\Interop\exceptions.py", line 13, in <module>
    raise Y
SubError: '4 is not less than three.'

Running the same code in Rhino's environment produces this:

Message: SubError

Traceback:
  line 13, in <module>, "C:\Users\frankfralick\AppData\Local\Temp\TempScript.py"

Not as useful. Does this have to do with how IronPython is being embedded (ScriptSource.Execute vs. ExecuteProgram or something like that)? If I insert a like "print Y" above "raise Y" it will print the exception message to the command prompt window it Rhino's UI, which will work for now but is not a good solution. Is there a way around this?

[Steve Baer]

This looks like something I probably need to fix in the embedded python interpreter. I don't have a good answer for what to do for the time being.