Hi,
environment: Python 2.4, GNU/Linux, kernel 2.6.12.2
having subclassed 'Exception' I'm trying to call the initialiser
__init__(...) of the superclass Exception with 'super(..).__in it__(..)' .
However, trying to do so results in a
'TypeError: super() argument 1 must be type, not classobj'.
Now, if I use 'Exception.__in it__(..)' instad of super(..)... ,everything
works just as one would expect.
Why does 'super(..).__in it__(..)' fail?
thank you for any suggestions
chriss
Here is some example code to illustrate the point:
class WorkingExceptio n(Exception):
def __init__(self, message):
# works as I would expect
Exception.__ini t__(self, message)
class BrokenException (Exception):
def __init__(self, message):
# fails with a typeError
super(BrokenExc eption, self).__init__( self, message)
# --------- case 1 ---------
try:
raise WorkingExceptio n("Hello WorkingExceptio n")
except WorkingExceptio n, e:
print e
# --------- case 3 ---------
try:
raise BrokenException ("Hello BrokenException ")
except BrokenException , e:
print e
3  5149 
chriss wrote: Hi,
environment: Python 2.4, GNU/Linux, kernel 2.6.12.2
having subclassed 'Exception' I'm trying to call the initialiser
__init__(...) of the superclass Exception with 'super(..).__in it__(..)' .
However, trying to do so results in a
'TypeError: super() argument 1 must be type, not classobj'.
Now, if I use 'Exception.__in it__(..)' instad of super(..)... ,everything
works just as one would expect.
Why does 'super(..).__in it__(..)' fail?
Exceptions do not inherit from 'object'; they are old-style classes.
super() can be used only with new-style classes (which subclass 'object').
-Peter
chriss wrote: Hi,
environment: Python 2.4, GNU/Linux, kernel 2.6.12.2
having subclassed 'Exception' I'm trying to call the initialiser
__init__(...) of the superclass Exception with 'super(..).__in it__(..)' .
However, trying to do so results in a
'TypeError: super() argument 1 must be type, not classobj'.
Now, if I use 'Exception.__in it__(..)' instad of super(..)... ,everything
works just as one would expect.
Why does 'super(..).__in it__(..)' fail?
AFAICT, the Exception hierarchy are still old-style classes while
super() only works on new-style classes.
--
Robert Kern rk***@ucsd.edu
"In the fields of hell where the grass grows high
Are the graves of dreams allowed to die."
-- Richard Harter
Peter Hansen wrote: chriss wrote: Hi,
environment: Python 2.4, GNU/Linux, kernel 2.6.12.2
having subclassed 'Exception' I'm trying to call the initialiser
__init__(...) of the superclass Exception with 'super(..).__in it__(..)' .
However, trying to do so results in a
'TypeError: super() argument 1 must be type, not classobj'.
Now, if I use 'Exception.__in it__(..)' instad of super(..)... ,everything
works just as one would expect.
Why does 'super(..).__in it__(..)' fail?
Exceptions do not inherit from 'object'; they are old-style classes.
super() can be used only with new-style classes (which subclass 'object').
-Peter
That explains it all right.
Thank you very much for your answer.
chriss This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics | |
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