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      1 
      2 :mod:`cgitb` --- Traceback manager for CGI scripts
      3 ==================================================
      4 
      5 .. module:: cgitb
      6    :synopsis: Configurable traceback handler for CGI scripts.
      7 .. moduleauthor:: Ka-Ping Yee <ping (a] lfw.org>
      8 .. sectionauthor:: Fred L. Drake, Jr. <fdrake (a] acm.org>
      9 
     10 
     11 .. versionadded:: 2.2
     12 
     13 .. index::
     14    single: CGI; exceptions
     15    single: CGI; tracebacks
     16    single: exceptions; in CGI scripts
     17    single: tracebacks; in CGI scripts
     18 
     19 The :mod:`cgitb` module provides a special exception handler for Python scripts.
     20 (Its name is a bit misleading.  It was originally designed to display extensive
     21 traceback information in HTML for CGI scripts.  It was later generalized to also
     22 display this information in plain text.)  After this module is activated, if an
     23 uncaught exception occurs, a detailed, formatted report will be displayed.  The
     24 report includes a traceback showing excerpts of the source code for each level,
     25 as well as the values of the arguments and local variables to currently running
     26 functions, to help you debug the problem.  Optionally, you can save this
     27 information to a file instead of sending it to the browser.
     28 
     29 To enable this feature, simply add this to the top of your CGI script::
     30 
     31    import cgitb
     32    cgitb.enable()
     33 
     34 The options to the :func:`enable` function control whether the report is
     35 displayed in the browser and whether the report is logged to a file for later
     36 analysis.
     37 
     38 
     39 .. function:: enable([display[, logdir[, context[, format]]]])
     40 
     41    .. index:: single: excepthook() (in module sys)
     42 
     43    This function causes the :mod:`cgitb` module to take over the interpreter's
     44    default handling for exceptions by setting the value of :attr:`sys.excepthook`.
     45 
     46    The optional argument *display* defaults to ``1`` and can be set to ``0`` to
     47    suppress sending the traceback to the browser. If the argument *logdir* is
     48    present, the traceback reports are written to files.  The value of *logdir*
     49    should be a directory where these files will be placed. The optional argument
     50    *context* is the number of lines of context to display around the current line
     51    of source code in the traceback; this defaults to ``5``. If the optional
     52    argument *format* is ``"html"``, the output is formatted as HTML.  Any other
     53    value forces plain text output.  The default value is ``"html"``.
     54 
     55 
     56 .. function:: handler([info])
     57 
     58    This function handles an exception using the default settings (that is, show a
     59    report in the browser, but don't log to a file). This can be used when you've
     60    caught an exception and want to report it using :mod:`cgitb`.  The optional
     61    *info* argument should be a 3-tuple containing an exception type, exception
     62    value, and traceback object, exactly like the tuple returned by
     63    :func:`sys.exc_info`.  If the *info* argument is not supplied, the current
     64    exception is obtained from :func:`sys.exc_info`.
     65 
     66