mirror of https://github.com/python/cpython
55 lines
2.4 KiB
TeX
55 lines
2.4 KiB
TeX
\section{Built-in module \sectcode{traceback}}
|
|
\stmodindex{traceback}
|
|
|
|
\renewcommand{\indexsubitem}{(in module traceback)}
|
|
|
|
This module provides a standard interface to format and print stack
|
|
traces of Python programs. It exactly mimics the behavior of the
|
|
Python interpreter when it prints a stack trace. This is useful when
|
|
you want to print stack traces under program control, e.g. in a
|
|
``wrapper'' around the interpreter.
|
|
|
|
The module uses traceback objects --- this is the object type
|
|
that is stored in the variables \code{sys.exc_traceback} and
|
|
\code{sys.last_traceback}.
|
|
|
|
The module defines the following functions:
|
|
|
|
\begin{funcdesc}{print_tb}{traceback\optional{\, limit}}
|
|
Print up to \var{limit} stack trace entries from \var{traceback}. If
|
|
\var{limit} is omitted or \code{None}, all entries are printed.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{extract_tb}{traceback\optional{\, limit}}
|
|
Return a list of up to \var{limit} ``pre-processed'' stack trace
|
|
entries extracted from \var{traceback}. It is useful for alternate
|
|
formatting of stack traces. If \var{limit} is omitted or \code{None},
|
|
all entries are extracted. A ``pre-processed'' stack trace entry is a
|
|
quadruple (\var{filename}, \var{line number}, \var{function name},
|
|
\var{line text}) representing the information that is usually printed
|
|
for a stack trace. The \var{line text} is a string with leading and
|
|
trailing whitespace stripped; if the source is not available it is
|
|
\code{None}.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{print_exception}{type\, value\, traceback\optional{\, limit}}
|
|
Print exception information and up to \var{limit} stack trace entries
|
|
from \var{traceback}. This differs from \code{print_tb} in the
|
|
following ways: (1) if \var{traceback} is not \code{None}, it prints a
|
|
header ``\code{Traceback (innermost last):}''; (2) it prints the
|
|
exception \var{type} and \var{value} after the stack trace; (3) if
|
|
\var{type} is \code{SyntaxError} and \var{value} has the appropriate
|
|
format, it prints the line where the syntax error occurred with a
|
|
caret indication the approximate position of the error.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{print_exc}{\optional{limit}}
|
|
This is a shorthand for \code{print_exception(sys.exc_type,}
|
|
\code{sys.exc_value,} \code{sys.exc_traceback,} \code{limit)}.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{print_last}{\optional{limit}}
|
|
This is a shorthand for \code{print_exception(sys.last_type,}
|
|
\code{sys.last_value,} \code{sys.last_traceback,} \code{limit)}.
|
|
\end{funcdesc}
|