all Python 3typesterm

types.TracebackType

interpreter objects

The type of an exception traceback: a chain of frames from where it was caught to where it was raised. Available as exc.__traceback__.

Syntax

exc.__traceback__

The chain goes through tb_next, and the failing line belongs to the last link, not the first: the first tb_lineno points at the line inside try. A saved exception keeps its traceback, and that keeps every frame with its local variables — which is why Python deletes the name from except ... as e at the end of the block. The traceback module produces ready text; walking the chain by hand is rarely needed.

Examples

import types
def inner():
    return 1 / 0
try:
    inner()
except ZeroDivisionError as e:
    tb = e.__traceback__
    print(isinstance(tb, types.TracebackType))  # → True
    while tb.tb_next:
        tb = tb.tb_next
    print(tb.tb_frame.f_code.co_name)  # → inner

See also

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