Только Python печатает трассировку поднятого исключения

Используйте with_traceback

import sys, traceback
try:
    10/0
except Exception as exc:
    raise  exc.with_traceback(None)

---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
 in ()
      3     10/0
      4 except Exception as exc:
----> 5     raise  exc.with_traceback(None)

ZeroDivisionError: division by zero

Если вы просто custom-exceptions хотите это показать:

import sys, traceback
try:
    10/0
except Exception:
    ex_type, ex, tb = sys.exc_info()
    traceback.print_tb(tb)

File "", line 3, in 
    10/0

АЛЬТЕРНАТИВА

import sys, traceback
try:
    10/0
except Exception as exc:
    tb_str = traceback.format_exception(etype=type(exc), value=exc, tb=exc.__traceback__)
    for i in tb_str: print(i)

Traceback (most recent call last):

  File "", line 3, in 
    10/0

ZeroDivisionError: division by zero