traceback.rst

Traceback

Traceback object is used to preserve all the information you can get in case of an exception. It preserves: * Information about all stack frames in this thread * Every local and global variable at every stack frame

• If the variable is picklable, and pickling is enabled, it is pickled on the spot
• Variable's _repr_ is always preserved
• Of course variable name is saved

It also allows to pretty print the exception. Traceback is picklable, so you can safely do so and analyze the exception at your own leisure.

Unpickling _Traceback_ objects in any environment is safe. However, obtaining variable values via _load_value_ might be not.

Usage:

from satella.instrumentation import Traceback

try:
    ...
except:
    tb = Traceback()

    print(tb.pretty_print())    # print stack trace

    tb_p = tb.pickle()  # pickles the traceback

Traceback should be created in the exception it is supposed to capture, as it captures exception info from _sys.exc_info()_. If no exception is in progress, current stack frame will be fetched from inspect.currentframe().

Alternatively, you can pass a <frame> object to Traceback, in order to serialize it, for example:

import sys

frame_1 = next(iter(sys._current_frames().values()))
tb = Traceback(frame_1)

There's a helper function as well

Dumping all stack frames