[Python-bugs-list] [ python-Bugs-666958 ] repr.repr not always safe

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Bugs item #666958, was opened at 2003-01-12 23:17
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=666958&group_id=5470

Category: Python Library
Group: Python 2.2
Status: Open
Resolution: None
Priority: 5
Submitted By: Bob Ippolito (etrepum)
Assigned to: Nobody/Anonymous (nobody)
Summary: repr.repr not always safe

Initial Comment:
>>> class A:
...   def __repr__(self):
...     raise Exception
...   def someMethod(self):
...     pass
... 
>>> A()
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "<stdin>", line 3, in __repr__
Exception
>>> repr.repr(A())
'<A instance at 237360>'
>>> repr.repr(A().someMethod)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "/usr/lib/python2.2/repr.py", line 15, in repr
    return self.repr1(x, self.maxlevel)
  File "/usr/lib/python2.2/repr.py", line 24, in repr1
    s = `x`
  File "<stdin>", line

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>Comment By: Tim Peters (tim_one)
Date: 2003-01-12 23:34

Message:
Logged In: YES 
user_id=31435

Why do say this is a bug?  If you raise an exception, yes, 
you get an exception.  Most __repr__ *implementations* 
try hard not to raise any exceptions, but it's never 
guaranteed that they won't.  For example, just about any 
__repr__ implementation may run out of memory while 
trying to build its result string, so MemoryError is almost 
always a possible exception.

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You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=666958&group_id=5470