Displaying error message in a try except?

[wawork]

Fairly new to python. In a try except how do you display the true
(raw) error message so it can be displayed back to the user?

[Fredrik Lundh]

wa****@hotmail. com wrote:

Fairly new to python. In a try except how do you display the true
(raw) error message so it can be displayed back to the user?

assuming that "true" means "the message you would get if you hadn't
used a try/except", the traceback module is what you want:

import traceback

try:
raise SyntaxError("ex ample")
except:
traceback.print _exc()

prints

Traceback (innermost last):
File "module.py" , line 4, in ?
SyntaxError: example

more here:

http://effbot.org/librarybook/traceback.htm

you can also inspect the exception status via the sys.exc_info() call.
e.g.

import sys

try:
1/0
except:
print "%s: %s" % sys.exc_info()[:2]

prints

exceptions.Zero DivisionError: integer division or modulo by zero

for more info, see the library reference.

hope this helps!

</F>

[Xavier Morel]

Fredrik Lundh wrote:

assuming that "true" means "the message you would get if you hadn't
used a try/except", the traceback module is what you want:

you can also inspect the exception status via the sys.exc_info() call.
e.g.

There is also the third way of catching an exception explicitly and
printing it's arguments and class (doesn't give exactly the same
information, but gives relevant informations nonetheless)

--

try:

1/0
except ZeroDivisionErr or, e:
print e
print e.args
print repr(e)
integer division or modulo by zero
('integer division or modulo by zero',)
<exceptions.Zer oDivisionError instance at 0x00E35850>
--

(catching Exception instead of ZeroDivisionErr or would yield the same
result, but would also act as an Exception trap that voids any exception
raised)