Re: Simple unicode-safe version of str(exception)?
Martin v. Löwis wrote: e is an exception object, not a Unicode object. Er, sure, thanks for pointing that out. At first sight he should substitute e with e.message then since he tries to convert to string (for display?). Regards, Björn -- BOFH excuse #366: ATM cell has no roaming feature turned on, notebooks can't connect -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
In article [EMAIL PROTECTED], Bjoern Schliessmann [EMAIL PROTECTED] wrote: Martin v. Löwis wrote: e is an exception object, not a Unicode object. Er, sure, thanks for pointing that out. At first sight he should substitute e with e.message then since he tries to convert to string (for display?). No. e.message is only set if the exeption object receives exactly one argument. That is why my replacement code reads: errStr = ,.join([unicode(s) for s in f.args]) self.setState(self.Failed, errStr) (where e is an Exception of some kind) Notice that I'm iterating over the args. But again, this is far messier than: self.setState(self.Failed, str(e) So...to repeat the original question, is there any simpler unicode-safe replacement for str(exception)? -- Russell -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
In article [EMAIL PROTECTED], Donn Cave [EMAIL PROTECTED] wrote: In article [EMAIL PROTECTED], Martin v. Löwis [EMAIL PROTECTED] wrote: I have code like this: except Exception, e: self.setState(self.Failed, str(e)) which fails if the exception contains a unicode argument. Fails how? ASCII encoding error, I suppose. It fails only if a) one argument is a Unicode object, and b) that Unicode object contains non-ASCII parameters. Seem ironic that this fails even though pretty nearly anything else is a valid input to str() -- socket, dict, whatever? I agree. In fact str(a) works if a is a dict or list that contains unicode data! Pity the same is not true of exceptions. Should I report this as a bug? I suspect it's a misfeature. A sort of generic solution might be to follow str's behavior with respect to '__str__', extending it to fall back to repr() whatever goes wrong. def xtr(a): try: return str(a) except: return repr(a) Yes. That is a more flexible alternative to what I've adopted: def exStr(ex): return ,.join([unicode(s) for s in f.args]) the latter gives better output for the case I'm interested in, but only handles exceptions. Oh well. I'll stick to my solution and hope that Python 2.6 and 3.0 fix the problem in a more sensible fashion. -- Russell -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
Hallöchen! Russell E. Owen writes: [...] So...to repeat the original question, is there any simpler unicode-safe replacement for str(exception)? Please show us the tracebacks you get becuae unicode(s) must fail, too, if there are non-ASCII characters involved. Tschö, Torsten. -- Torsten Bronger, aquisgrana, europa vetus Jabber ID: [EMAIL PROTECTED] (See http://ime.webhop.org for further contact info.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
Russell E. Owen [EMAIL PROTECTED] wrote: No. e.message is only set if the exeption object receives exactly one argument. And not always then: e1 = Exception(u\u00fe) e1.message Traceback (most recent call last): File stdin, line 1, in ? AttributeError: Exception instance has no attribute 'message' That is why my replacement code reads: errStr = ,.join([unicode(s) for s in f.args]) errStr = ,.join(e.args) There is something distinctly odd going on here, though: str(e1) Traceback (most recent call last): File stdin, line 1, in ? UnicodeEncodeError: 'ascii' codec can't encode character u'\xfe' in position 0: ordinal not in range(128) e2 = Exception(u\u00fe, foo) str(e2) (u'\\xfe', 'foo') -- \S -- [EMAIL PROTECTED] -- http://www.chaos.org.uk/~sion/ Frankly I have no feelings towards penguins one way or the other -- Arthur C. Clarke her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
In article [EMAIL PROTECTED],
Torsten Bronger [EMAIL PROTECTED] wrote:
Hallöchen!
Russell E. Owen writes:
[...]
So...to repeat the original question, is there any simpler
unicode-safe replacement for str(exception)?
Please show us the tracebacks you get becuae unicode(s) must fail,
too, if there are non-ASCII characters involved.
Why?
What I am trying to do is get a unicode representation of the arguments
of an exception. str(e), the obvious solution, fails if the exception
contains one argument that is a unicode string that cannot be decoded to
ASCII:
UnicodeEncodeError: 'ascii' codec can't encode character...ordinal not
in range(128)
What I do with the resulting unicode string afterwards is a different
issue. (As a matter of fact I display it on a widget that can display
unicode, but if I tried to print it to my Mac Terminal it would complain
about the non-ASCII characters--something I should look into fixing
someday).
But in any case, here are the exceptions you wanted to see. This is
using Python 2.5.2 on a Mac:
d =u\N{DEGREE SIGN}
d
u'\xb0'
str(d)
Traceback (most recent call last):
File stdin, line 1, in module
UnicodeEncodeError: 'ascii' codec can't encode character u'\xb0' in
position 0: ordinal not in range(128)
e = Exception(d)
str(e)
Traceback (most recent call last):
File stdin, line 1, in module
UnicodeEncodeError: 'ascii' codec can't encode character u'\xb0' in
position 0: ordinal not in range(128)
e
Exception(u'\xb0',)
,.join([unicode(s) for s in e.args])
u'\xb0'
Based on the dearth of better replacements I've gone with the solution
that is shown as the last line above, coded as the following function
(incorporating Donn Cave's excellent suggestion to use repr as a
fallback). It has the minor issue that it can mask KeyboardInterrupt on
older versions of Python but it's close enough. A lot of work to replace
str(exc).
def strFromException(exc):
Unicode-safe replacement for str(exception)
try:
return str(exc)
except Exception:
try:
return ,.join([unicode(s) for s in exc.args])
except Exception:
# in case exc is some unexpected type
return repr(exc)
-- Russell
--
http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
Hallöchen! Russell E. Owen writes: Torsten Bronger [EMAIL PROTECTED] wrote: Russell E. Owen writes: [...] So...to repeat the original question, is there any simpler unicode-safe replacement for str(exception)? Please show us the tracebacks you get becuae unicode(s) must fail, too, if there are non-ASCII characters involved. Why? [...] ,.join([unicode(s) for s in e.args]) u'\xb0' I thought you wanted to have a string. But this is again a unicode. Tschö, Torsten. -- Torsten Bronger, aquisgrana, europa vetus Jabber ID: [EMAIL PROTECTED] (See http://ime.webhop.org for further contact info.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
Should I report this as a bug? I suspect it's a misfeature. Please no. There isn't much that can be done about it, IMO. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
Hallöchen! Martin v. Löwis writes: Should I report this as a bug? I suspect it's a misfeature. Please no. There isn't much that can be done about it, IMO. One could give Exception a __unicode__ method. On the other hand, this kind of conversion of an exception to something printable is a quite ugly kludge anyway in my opinion, so it needn't special support. Tschö, Torsten. -- Torsten Bronger, aquisgrana, europa vetus Jabber ID: [EMAIL PROTECTED] (See http://ime.webhop.org for further contact info.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
I often struggle with the problem outlined in part in this thread. I know that I'm going to repeat some of what is said elsewhere but I'd like to present the question all in one place. I believe that the routines in the Python standard library do not document which exceptions they could raise (I understand some reasons why, but they nontheless do not). So I often find out the hard way that a library call can raise an exception that I was not smart enough to anticipate. So I often find myself doing try: make_a_routine_call(x,y,z) except AnticipatedError, err: do_something_with_it(x,y,z,err) exception Exception, err: print something crazy happened +str(err) where the print statement is just supposed to give me some idea of what happened. (I actually usually log it instead of printing it. If there is a better way, I'd love to hear it.) But str(err) sometimes fails, as the OP noted. Further, xtr(err) alone is not enough, I believe. I believe that some routines in the standard library do not return strings (by that I mean something approximately like err.value is a pair; forgive me, I don't remember the full details). Surely as lovely a language as Python has a better idiom for dealing with exceptions in the standard library than something that works out to print something crazy happened+ .join([xtra(x) for x in err]) ? (I would understand better if it was a user's code; they are free to do what works for them, of course.) But I've been unable to think of one and I haven't seen in this thread another direction. Is there one? Jim -- http://mail.python.org/mailman/listinfo/python-list
Simple unicode-safe version of str(exception)?
I have code like this: except Exception, e: self.setState(self.Failed, str(e)) which fails if the exception contains a unicode argument. I did, of course, try unicode(e) but that fails. The following works, but seems rather messy: except Exception, e: errStr = ,.join([unicode(s) for s in f.args]) self.setState(self.Failed, errStr) Is there a simpler solution that works in Python 2.3-2.5? -- Russell -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
Russell E. Owen wrote: I have code like this: except Exception, e: self.setState(self.Failed, str(e)) which fails if the exception contains a unicode argument. Fails how? I did, of course, try unicode(e) but that fails. Converting unicode to unicode doesn't help. Instead of just e, try using e.encode(some-encoding) where some-encoding should be your system's default encoding like utf-8 or iso8859-1. Regards, Björn -- BOFH excuse #434: Please state the nature of the technical emergency -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
I have code like this: except Exception, e: self.setState(self.Failed, str(e)) which fails if the exception contains a unicode argument. Fails how? ASCII encoding error, I suppose. It fails only if a) one argument is a Unicode object, and b) that Unicode object contains non-ASCII parameters. I did, of course, try unicode(e) but that fails. Converting unicode to unicode doesn't help. e is an exception object, not a Unicode object. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple unicode-safe version of str(exception)?
In article [EMAIL PROTECTED], Martin v. Löwis [EMAIL PROTECTED] wrote: I have code like this: except Exception, e: self.setState(self.Failed, str(e)) which fails if the exception contains a unicode argument. Fails how? ASCII encoding error, I suppose. It fails only if a) one argument is a Unicode object, and b) that Unicode object contains non-ASCII parameters. Seem ironic that this fails even though pretty nearly anything else is a valid input to str() -- socket, dict, whatever? A sort of generic solution might be to follow str's behavior with respect to '__str__', extending it to fall back to repr() whatever goes wrong. def xtr(a): try: return str(a) except: return repr(a) ... self.setState(self.Failed, xtr(e)) Donn Cave, [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
