Re: exception handling for a function returning several values

[Steven Bethard]

[EMAIL PROTECTED] wrote:
If a function that normally returns N values raises an exception, what
should it return?
Depends on what you want to do with the result of the function.
N values of None seems reasonable to me, so I would
write code such as
def foo(x):
    try:
       # code setting y and z
       return y,z
    except:
       return None,None
y,z = foo(x)
You almost never want a bare except.  What exception are you catching?
My suspicion is that the code would be better written as:
def foo(x):
    # code settying y and z
    return y, z
try:
    y, z = foo(x)
except FooError:
    y, z = None, None
but I'm not sure if you really want y and z to be None if foo fails. 
What do you do with y and z?

Steve
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