Function format_exception_only

Lib/traceback.py:172–191

Format the exception part of a traceback. The return value is a list of strings, each ending in a newline. The list contains the exception's message, which is normally a single string; however, for :exc:`SyntaxError` exceptions, it contains several lines that (when printed) display

(exc, /, value=_sentinel, *, show_group=False, **kwargs)

def format_exception_only(exc, /, value=_sentinel, *, show_group=False, **kwargs):
    """Format the exception part of a traceback.

    The return value is a list of strings, each ending in a newline.

    The list contains the exception's message, which is
    normally a single string; however, for :exc:`SyntaxError` exceptions, it
    contains several lines that (when printed) display detailed information
    about where the syntax error occurred. Following the message, the list
    contains the exception's ``__notes__``.

    When *show_group* is ``True``, and the exception is an instance of
    :exc:`BaseExceptionGroup`, the nested exceptions are included as
    well, recursively, with indentation relative to their nesting depth.
    """
    colorize = kwargs.get("colorize", False)
    if value is _sentinel:
        value = exc
    te = TracebackException(type(value), value, None, compact=True)
    return list(te.format_exception_only(show_group=show_group, colorize=colorize))


# -- not official API but folk probably use these two functions.