Class TracebackException

Lib/traceback.py:1024–1644

An exception ready for rendering. The traceback module captures enough attributes from the original exception to this intermediary form to ensure that no references are held, while still being able to fully print or format it. max_group_width and max_group_depth control the formatt

class TracebackException:
    """An exception ready for rendering.

    The traceback module captures enough attributes from the original exception
    to this intermediary form to ensure that no references are held, while
    still being able to fully print or format it.

    max_group_width and max_group_depth control the formatting of exception
    groups. The depth refers to the nesting level of the group, and the width
    refers to the size of a single exception group's exceptions array. The
    formatted output is truncated when either limit is exceeded.

    Use `from_exception` to create TracebackException instances from exception
    objects, or the constructor to create TracebackException instances from
    individual components.

    - :attr:`__cause__` A TracebackException of the original *__cause__*.
    - :attr:`__context__` A TracebackException of the original *__context__*.
    - :attr:`exceptions` For exception groups - a list of TracebackException
      instances for the nested *exceptions*.  ``None`` for other exceptions.
    - :attr:`__suppress_context__` The *__suppress_context__* value from the
      original exception.
    - :attr:`stack` A `StackSummary` representing the traceback.
    - :attr:`exc_type` (deprecated) The class of the original traceback.
    - :attr:`exc_type_str` String display of exc_type
    - :attr:`filename` For syntax errors - the filename where the error
      occurred.
    - :attr:`lineno` For syntax errors - the linenumber where the error
      occurred.
    - :attr:`end_lineno` For syntax errors - the end linenumber where the error
      occurred. Can be `None` if not present.
    - :attr:`text` For syntax errors - the text where the error
      occurred.
    - :attr:`offset` For syntax errors - the offset into the text where the
      error occurred.
    - :attr:`end_offset` For syntax errors - the end offset into the text where
      the error occurred. Can be `None` if not present.
    - :attr:`msg` For syntax errors - the compiler error message.
    """

    def __init__(self, exc_type, exc_value, exc_traceback, *, limit=None,
            lookup_lines=True, capture_locals=False, compact=False,
            max_group_width=15, max_group_depth=10, save_exc_type=True, _seen=None):
        # NB: we need to accept exc_traceback, exc_value, exc_traceback to
        # permit backwards compat with the existing API, otherwise we
        # need stub thunk objects just to glue it together.
        # Handle loops in __cause__ or __context__.
        is_recursive_call = _seen is not None
        if _seen is None:
            _seen = set()
        _seen.add(id(exc_value))

        self.max_group_width = max_group_width
        self.max_group_depth = max_group_depth

        self.stack = StackSummary._extract_from_extended_frame_gen(
            _walk_tb_with_full_positions(exc_traceback),
            limit=limit, lookup_lines=lookup_lines,