I have some code that handles an exception, and I want to do something specific only if it's a specific exception, and only in debug mode. So for example:
try:
stuff()
except Exception as e:
if _debug and e is KeyboardInterrupt:
sys.exit()
logging.exception("Normal handling")
As such, I don't want to just add a:
except KeyboardInterrupt:
sys.exit()
because I'm trying to keep the difference in this debug code minimal
Well, really, you probably should keep the handler for KeyboardInterrupt separated. Why would you only want to handle keyboard interrupts in debug mode, but swallow them otherwise?
That said, you can use isinstance to check the type of an object:
try:
stuff()
except Exception as e:
if _debug and isinstance(e, KeyboardInterrupt):
sys.exit()
logger.exception("Normal handling")
This is pretty much the way it's done.
try:
stuff()
except KeyboardInterrupt:
if _debug:
sys.exit()
logging.exception("Normal handling")
except Exception as e:
logging.exception("Normal handling")
There's minimal repetition. Not zero, however, but minimal.
If the "normal handling" is more than one line of code, you can define a function to avoid repetition of the two lines of code.
Either use the standard method mentioned in the other answers, or if you really want to test within the except block then you can use isinstance().
try:
stuff()
except Exception as e:
if _debug and isinstance(e, KeyboardInterrupt):
sys.exit()
logging.exception("Normal handling")
You should let KeyboardInterrupt bubble all the way up and trap it at the highest level.
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
sys.exit()
except:
pass
def main():
try:
stuff()
except Exception as e:
logging.exception("Normal handling")
if _debug:
raise e
try:
stuff()
except KeyboardInterrupt:
if _debug:
sys.exit()
logging.exception("Normal handling")
except ValueError:
if _debug:
sys.exit()
logging.exception("Value error Normal handling")
else:
logging.info("One more message without exception")
What's wrong with
try:
stuff()
except KeyboardInterrupt:
if _debug:
logging.exception("Debug handling")
sys.exit()
else:
logging.exception("Normal handling")
You can name specific exceptions in Python:
try:
stuff()
except KeyboardInterrupt:
sys.exit()
except Exception:
normal_handling()
