different behaviour for user defined exception with attribute args

2009-09-29 Thread Visco Shaun 
Hi all

For an exception defined as below

class OptionError(Exception):
def __init__(self, args):
self.args = args
def __str__(self):
return repr(self.v)

an iteration is happening when the exception is raised

Meanwhile for almost the same structured exception replacing the
attribute 'args' with say 'value' it is not a probs.

class OptionError(Exception):
def __init__(self, args):
self.value = args
def __str__(self):
return repr(self.value)

This was frustrating because for a st. OptionError('Error') for
exception 1 output will be

OptionError: ('E', 'r', 'r', 'o', 'r') 

Meanwhile for exception 2 output will be 

OptionError: 'Error'

which is desired..Why this behaviour?

Regards
Visco

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Re: different behaviour for user defined exception with attribute args

2009-09-29 Thread M.-A. Lemburg 
Visco Shaun wrote:
 Hi all
 
 For an exception defined as below
 
 class OptionError(Exception):
 def __init__(self, args):
 self.args = args

This should read:

def __init__(self, *args):
self.args = args

(notice the * !)

self.args holds the constructor argument tuple or list, not
a single value.

 def __str__(self):
 return repr(self.v)
 
 an iteration is happening when the exception is raised
 
 Meanwhile for almost the same structured exception replacing the
 attribute 'args' with say 'value' it is not a probs.
 
 class OptionError(Exception):
 def __init__(self, args):
 self.value = args
 def __str__(self):
 return repr(self.value)
 
 This was frustrating because for a st. OptionError('Error') for
 exception 1 output will be
 
 OptionError: ('E', 'r', 'r', 'o', 'r') 
 
 Meanwhile for exception 2 output will be 
 
 OptionError: 'Error'
 
 which is desired..Why this behaviour?

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eGenix.com

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Re: different behaviour for user defined exception with attribute args

2009-09-29 Thread Dave Angel 

Visco Shaun wrote:

Hi all

For an exception defined as below

class OptionError(Exception):
def __init__(self, args):
self.args = args
def __str__(self):
return repr(self.v)

an iteration is happening when the exception is raised

snip

  
What is self.v intended to produce?   Perhaps you meant self.args ??  
That doesn't explain your error though.  I suspect you didn't quote your 
code accurately.


The other problem is that args is intended to be a tuple.  So you want 
to use *args for your formal parameter.


DaveA


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