is parameter an iterable?

[Fredrik Lundh]

Rick Wotnaz wrote.

> ... which leads me to belive that 'msg' is not type(str). It can be
> coerced (str(msg).find works as expected). But what exactly is msg?
> It appears to be of <type 'instance'>, and does not test equal to a
> string.

it's an instance of the exception type, of course.

:::

if you do

    raise SomeError, value

Python will actually do

    raise SomeError(value)

(that is, create a SomeError exception and pass the value as its
first argument).

you can use either form in your code (I prefer the latter myself).

:::

as for catching the exceptions, if you do

    try:
        ...
    except SomeError, v:
        ...

Python will treat this as

    try:
        ...
    except:
        # some exception occurred
        typ = sys.exc_type
        exc = sys.exc_value
        if issubclass(typ, SomeError):
            v = exc
            ...
        else:
            raise # propagate!

(where typ and exc are internal variables)

</F>