Mercurial > cpython-lru_cache-weakref
annotate Doc/lib/libtraceback.tex @ 5817:48b94de85bf3 legacy-trunk
Extensive changes by AMK.
| author | Guido van Rossum <guido@python.org> |
|---|---|
| date | Thu, 17 Jul 1997 16:29:42 +0000 |
| parents | f47bc5554418 |
| children | 3468ea8645ca |
| rev | line source |
|---|---|
|
2576
f47bc5554418
mass changes; fix titles; add examples; correct typos; clarifications;
Guido van Rossum <guido@python.org>
parents:
2460
diff
changeset
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1 \section{Standard Module \sectcode{traceback}} |
| 2460 | 2 \stmodindex{traceback} |
| 3 | |
| 4 \renewcommand{\indexsubitem}{(in module traceback)} | |
| 5 | |
| 6 This module provides a standard interface to format and print stack | |
| 7 traces of Python programs. It exactly mimics the behavior of the | |
| 8 Python interpreter when it prints a stack trace. This is useful when | |
| 9 you want to print stack traces under program control, e.g. in a | |
| 10 ``wrapper'' around the interpreter. | |
| 11 | |
| 12 The module uses traceback objects --- this is the object type | |
| 13 that is stored in the variables \code{sys.exc_traceback} and | |
| 14 \code{sys.last_traceback}. | |
| 15 | |
| 16 The module defines the following functions: | |
| 17 | |
| 18 \begin{funcdesc}{print_tb}{traceback\optional{\, limit}} | |
| 19 Print up to \var{limit} stack trace entries from \var{traceback}. If | |
| 20 \var{limit} is omitted or \code{None}, all entries are printed. | |
| 21 \end{funcdesc} | |
| 22 | |
| 23 \begin{funcdesc}{extract_tb}{traceback\optional{\, limit}} | |
| 24 Return a list of up to \var{limit} ``pre-processed'' stack trace | |
| 25 entries extracted from \var{traceback}. It is useful for alternate | |
| 26 formatting of stack traces. If \var{limit} is omitted or \code{None}, | |
| 27 all entries are extracted. A ``pre-processed'' stack trace entry is a | |
| 28 quadruple (\var{filename}, \var{line number}, \var{function name}, | |
| 29 \var{line text}) representing the information that is usually printed | |
| 30 for a stack trace. The \var{line text} is a string with leading and | |
| 31 trailing whitespace stripped; if the source is not available it is | |
| 32 \code{None}. | |
| 33 \end{funcdesc} | |
| 34 | |
| 35 \begin{funcdesc}{print_exception}{type\, value\, traceback\optional{\, limit}} | |
| 36 Print exception information and up to \var{limit} stack trace entries | |
| 37 from \var{traceback}. This differs from \code{print_tb} in the | |
| 38 following ways: (1) if \var{traceback} is not \code{None}, it prints a | |
| 39 header ``\code{Traceback (innermost last):}''; (2) it prints the | |
| 40 exception \var{type} and \var{value} after the stack trace; (3) if | |
| 41 \var{type} is \code{SyntaxError} and \var{value} has the appropriate | |
| 42 format, it prints the line where the syntax error occurred with a | |
| 43 caret indication the approximate position of the error. | |
| 44 \end{funcdesc} | |
| 45 | |
| 46 \begin{funcdesc}{print_exc}{\optional{limit}} | |
| 47 This is a shorthand for \code{print_exception(sys.exc_type,} | |
| 48 \code{sys.exc_value,} \code{sys.exc_traceback,} \code{limit)}. | |
| 49 \end{funcdesc} | |
| 50 | |
| 51 \begin{funcdesc}{print_last}{\optional{limit}} | |
| 52 This is a shorthand for \code{print_exception(sys.last_type,} | |
| 53 \code{sys.last_value,} \code{sys.last_traceback,} \code{limit)}. | |
| 54 \end{funcdesc} |