CODEWITHSUNDEEP
pythonpython-2.7
user1050619
user1050619

Reputation: 20866

Getting line number from the exception object

I have defined a custom Exception object and would like to get the line number of the exception.

class FlowException(Exception):
    pass

def something():
    print 2/3
    print 1/2
    print 2/0


try:
   something()
except Exception as e:
   raise FlowException("Process Exception", e)

Now, if there is a exception in something() it throws the FlowException but it does not give me the exact line number, How can I get the line number from FlowException(ie; it failed when it executed 2/0)?

Here is the output:--

raise FlowException("Process Exception", e)
__main__.FlowException: ('Process Exception', ZeroDivisionError('integer division or modulo by zero',))
[Finished in 0.4s with exit code 1]

Upvotes: 5

Views: 8264

Answers (2)

Diman
Diman

Reputation: 418

Tested on Python 3.6

class FlowException(Exception):
    pass

def something():
    raise ValueError

try:
   something()
except Exception as e:
    raise FlowException("Process Exception", e)

Output has line numbers:

Traceback (most recent call last):
  File "/Users/diman/PycharmProjects/invites/test.py", line 8, in <module>
    something()
  File "/Users/diman/PycharmProjects/invites/test.py", line 5, in something
    raise ValueError
ValueError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/diman/PycharmProjects/invites/test.py", line 10, in <module>
    raise FlowException("Process Exception", e)
__main__.FlowException: ('Process Exception', ValueError())

For Python 2 try using internal logger ".exception()" method instead of using monstrous "sys" module.

import logging
logger = logging.getLogger()

try:
    something()
except Exception as e:
    logger.exception(e)
    raise FlowException("Process Exception", e)

Upvotes: 0

user2390182
user2390182

Reputation: 73470

The traceback object holds that info in the tb_lineno attribute:

import sys

# ...
except Exception as e:
   trace_back = sys.exc_info()[2]
   line = trace_back.tb_lineno
   raise FlowException("Process Exception in line {}".format(line), e)

Upvotes: 6

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