Notebook

In [20]:

import sys, traceback

try:
    1/0
except Exception as e:
    print(e)
    print(type(e))
    print(e.args)    
    print(vars(sys.exc_info()[0]))
    print(vars(sys.exc_info()[1]))
    print(sys.exc_info())
    print(type(sys.exc_info()[1]), sys.exc_info()[1]) 

division by zero
<class 'ZeroDivisionError'>
('division by zero',)
{'__init__': <slot wrapper '__init__' of 'ZeroDivisionError' objects>, '__new__': <built-in method __new__ of type object at 0x55be2f196ce0>, '__doc__': 'Second argument to a division or modulo operation was zero.'}
{}
(<class 'ZeroDivisionError'>, ZeroDivisionError('division by zero',), <traceback object at 0x7faa0443a0c8>)
<class 'ZeroDivisionError'> division by zero

In [44]:

import sys
sys.exc_info()

Out[44]:

(None, None, None)

In [7]:

import sys
try:
    a
except ZeroDivisionError:
    print('--> ZeroDivisionError!')
except as e:
    print("--> except: ", )
    raise
else:
    print('--> no except!')
finally:
    print('--> always!')

--> except:  (<class 'NameError'>, NameError("name 'a' is not defined",))
--> always!

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-7-4ff509892040> in <module>()
      1 import sys
      2 try:
----> 3     a
      4 except ZeroDivisionError:
      5     print('--> ZeroDivisionError!')

NameError: name 'a' is not defined

https://docs.python.org/3/library/traceback.html

traceback.print_tb(tb, limit=None, file=None) traceback.print_exception(etype, value, tb, limit=None, file=None, chain=True) traceback.print_exc(limit=None, file=None, chain=True)

In [39]:

import sys, traceback

def main():
    my_exc()

def my_exc():
    return 1/0

try:
    main()
except Exception:
    exc_type, exc_value, exc_traceback = sys.exc_info()
    print("*** print_tb: (too simple)")
    traceback.print_tb(exc_traceback, limit=2, file=sys.stdout)
    print()
    
    print("*** print_exception: (hard to call)")
    # exc_type below is ignored on 3.5 and later
    traceback.print_exception(exc_type, exc_value, exc_traceback,
                              limit=2, file=sys.stdout)
    print()
    
    print("*** print_exc: (best?)")
    traceback.print_exc(file=sys.stdout)
    print()
    
    print("*** format_exc: (return str)")
    formatted_lines = traceback.format_exc()
    print(traceback.format_exc())
    print()
    
    print("*** format_exception:")
    # exc_type below is ignored on 3.5 and later
    print(repr(traceback.format_exception(exc_type, exc_value,
                                          exc_traceback)))
    print()
    
    print("*** extract_tb:")
    print(repr(traceback.extract_tb(exc_traceback)))
    print()
    
    print("*** format_tb:")
    print(repr(traceback.format_tb(exc_traceback)))
    print()
    
    print("*** tb_lineno:", exc_traceback.tb_lineno)

*** print_tb: (too simple)
  File "<ipython-input-39-876ae2ac6b33>", line 10, in <module>
    main()
  File "<ipython-input-39-876ae2ac6b33>", line 4, in main
    my_exc()

*** print_exception: (hard to call)
Traceback (most recent call last):
  File "<ipython-input-39-876ae2ac6b33>", line 10, in <module>
    main()
  File "<ipython-input-39-876ae2ac6b33>", line 4, in main
    my_exc()
ZeroDivisionError: division by zero

*** print_exc: (best?)
Traceback (most recent call last):
  File "<ipython-input-39-876ae2ac6b33>", line 10, in <module>
    main()
  File "<ipython-input-39-876ae2ac6b33>", line 4, in main
    my_exc()
  File "<ipython-input-39-876ae2ac6b33>", line 7, in my_exc
    return 1/0
ZeroDivisionError: division by zero

*** format_exc: (return str)
Traceback (most recent call last):
  File "<ipython-input-39-876ae2ac6b33>", line 10, in <module>
    main()
  File "<ipython-input-39-876ae2ac6b33>", line 4, in main
    my_exc()
  File "<ipython-input-39-876ae2ac6b33>", line 7, in my_exc
    return 1/0
ZeroDivisionError: division by zero


*** format_exception:
['Traceback (most recent call last):\n', '  File "<ipython-input-39-876ae2ac6b33>", line 10, in <module>\n    main()\n', '  File "<ipython-input-39-876ae2ac6b33>", line 4, in main\n    my_exc()\n', '  File "<ipython-input-39-876ae2ac6b33>", line 7, in my_exc\n    return 1/0\n', 'ZeroDivisionError: division by zero\n']

*** extract_tb:
[<FrameSummary file <ipython-input-39-876ae2ac6b33>, line 10 in <module>>, <FrameSummary file <ipython-input-39-876ae2ac6b33>, line 4 in main>, <FrameSummary file <ipython-input-39-876ae2ac6b33>, line 7 in my_exc>]

*** format_tb:
['  File "<ipython-input-39-876ae2ac6b33>", line 10, in <module>\n    main()\n', '  File "<ipython-input-39-876ae2ac6b33>", line 4, in main\n    my_exc()\n', '  File "<ipython-input-39-876ae2ac6b33>", line 7, in my_exc\n    return 1/0\n']

*** tb_lineno: 10