Python stacktrace module traceback line error

Question

I have the following Python program:

import traceback
import sys

try:

    3/0
except OverflowError as e:
    exc_type, exc_value, exc_traceback = sys.exc_info()
    formatted_lines = traceback.format_exc().splitlines()

    print(" It looks like in the arithmetic operation :" , formatted_lines[2], " )  #gets the offending line
    print (at line number " , exc_traceback.tb_lineno )  #gets the line number

except ZeroDivisionError as e:
   exc_type, exc_value, exc_traceback = sys.exc_info()
   formatted_lines = traceback.format_exc().splitlines()
   print(" It looks like in the arithmetic operation :" , formatted_lines[2], " )  #gets the offending line
   print (at line number " , exc_traceback.tb_lineno )  #gets t

For simple programs as above the stacktrace returns the correct line number, but for more complicated methods like below Python throws more stacktraces (the latest call being the last), is there a way to figure out the index of the stacktrace ex: formatted_lines[2] to get the latest call.

try:
 def prize():
    print("hello")

 def main():
    prize()

Catch:
.....

any help would be appreciated.

---

Also tried this:

import traceback
import sys
import linecache


try:

      2/0

except ZeroDivisionError as e:
        filename = exc_traceback.tb_frame.f_code.co_filename
        lineno = exc_traceback.tb_lineno
        line = linecache.getline(filename, lineno)
        print "exception occurred at %s:%d: %s" % (filename, lineno, line)

I get an error on the last line "invalid syntax"

When I just try:

print  (filename, lineno, line)

I get an error:

 Traceback (most recent call last):
  File "C:\Users\Anu\Desktop\test.py", line 39, in <module>
    filename = exc_traceback.tb_frame.f_code.co_filename
NameError: name 'exc_traceback' is not defined

Answer 1

Please don't try to parse stack traces using the output of format_exc . That's only meant to produce a human-readable stack trace.

You should instead use linecache to get the offending line:

exc_type, exc_value, exc_traceback = sys.exc_info()
filename = exc_traceback.tb_frame.f_code.co_filename
lineno = exc_traceback.tb_lineno
line = linecache.getline(filename, lineno)
print("exception occurred at %s:%d: %s" % (filename, lineno, line))