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"""More comprehensive traceback formatting for Python scripts.
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To enable this module, do:

    import cgitb; cgitb.enable()
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at the top of your script.  The optional arguments to enable() are:
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    display     - if true, tracebacks are displayed in the web browser
    logdir      - if set, tracebacks are written to files in this directory
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    context     - number of lines of source code to show for each stack frame
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    format      - 'text' or 'html' controls the output format
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By default, tracebacks are displayed but not saved, the context is 5 lines
and the output format is 'html' (for backwards compatibility with the
original use of this module)
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Alternatively, if you have caught an exception and want cgitb to display it
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for you, call cgitb.handler().  The optional argument to handler() is a
3-item tuple (etype, evalue, etb) just like the value of sys.exc_info().
The default handler displays output as HTML.
"""
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__author__ = 'Ka-Ping Yee'
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__version__ = '$Revision$'
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import sys
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def reset():
    """Return a string that resets the CGI and browser to a known state."""
    return '''<!--: spam
Content-Type: text/html
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<body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> -->
<body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> -->
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</font> </font> </font> </script> </object> </blockquote> </pre>
</table> </table> </table> </table> </table> </font> </font> </font>'''
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__UNDEF__ = []                          # a special sentinel object
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def small(text):
    if text:
        return '<small>' + text + '</small>'
    else:
        return ''
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def strong(text):
    if text:
        return '<strong>' + text + '</strong>'
    else:
        return ''
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def grey(text):
    if text:
        return '<font color="#909090">' + text + '</font>'
    else:
        return ''
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def lookup(name, frame, locals):
    """Find the value for a given name in the given environment."""
    if name in locals:
        return 'local', locals[name]
    if name in frame.f_globals:
        return 'global', frame.f_globals[name]
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    if '__builtins__' in frame.f_globals:
        builtins = frame.f_globals['__builtins__']
        if type(builtins) is type({}):
            if name in builtins:
                return 'builtin', builtins[name]
        else:
            if hasattr(builtins, name):
                return 'builtin', getattr(builtins, name)
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    return None, __UNDEF__

def scanvars(reader, frame, locals):
    """Scan one logical line of Python and look up values of variables used."""
    import tokenize, keyword
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    vars, lasttoken, parent, prefix, value = [], None, None, '', __UNDEF__
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    for ttype, token, start, end, line in tokenize.generate_tokens(reader):
        if ttype == tokenize.NEWLINE: break
        if ttype == tokenize.NAME and token not in keyword.kwlist:
            if lasttoken == '.':
                if parent is not __UNDEF__:
                    value = getattr(parent, token, __UNDEF__)
                    vars.append((prefix + token, prefix, value))
            else:
                where, value = lookup(token, frame, locals)
                vars.append((token, where, value))
        elif token == '.':
            prefix += lasttoken + '.'
            parent = value
        else:
            parent, prefix = None, ''
        lasttoken = token
    return vars

def html((etype, evalue, etb), context=5):
    """Return a nice HTML document describing a given traceback."""
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    import os, types, time, traceback, linecache, inspect, pydoc
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    if type(etype) is types.ClassType:
        etype = etype.__name__
    pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
    date = time.ctime(time.time())
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    head = '<body bgcolor="#f0f0f8">' + pydoc.html.heading(
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        '<big><big>%s</big></big>' %
        strong(pydoc.html.escape(str(etype))),
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        '#ffffff', '#6622aa', pyver + '<br>' + date) + '''
<p>A problem occurred in a Python script.  Here is the sequence of
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function calls leading up to the error, in the order they occurred.</p>'''
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    indent = '<tt>' + small('&nbsp;' * 5) + '&nbsp;</tt>'
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    frames = []
    records = inspect.getinnerframes(etb, context)
    for frame, file, lnum, func, lines, index in records:
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        if file:
            file = os.path.abspath(file)
            link = '<a href="file://%s">%s</a>' % (file, pydoc.html.escape(file))
        else:
            file = link = '?'
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        args, varargs, varkw, locals = inspect.getargvalues(frame)
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        call = ''
        if func != '?':
            call = 'in ' + strong(func) + \
                inspect.formatargvalues(args, varargs, varkw, locals,
                    formatvalue=lambda value: '=' + pydoc.html.repr(value))

        highlight = {}
        def reader(lnum=[lnum]):
            highlight[lnum[0]] = 1
            try: return linecache.getline(file, lnum[0])
            finally: lnum[0] += 1
        vars = scanvars(reader, frame, locals)

        rows = ['<tr><td bgcolor="#d8bbff">%s%s %s</td></tr>' %
                ('<big>&nbsp;</big>', link, call)]
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        if index is not None:
            i = lnum - index
            for line in lines:
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                num = small('&nbsp;' * (5-len(str(i))) + str(i)) + '&nbsp;'
                line = '<tt>%s%s</tt>' % (num, pydoc.html.preformat(line))
                if i in highlight:
                    rows.append('<tr><td bgcolor="#ffccee">%s</td></tr>' % line)
                else:
                    rows.append('<tr><td>%s</td></tr>' % grey(line))
                i += 1

        done, dump = {}, []
        for name, where, value in vars:
            if name in done: continue
            done[name] = 1
            if value is not __UNDEF__:
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                if where in ('global', 'builtin'):
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                    name = ('<em>%s</em> ' % where) + strong(name)
                elif where == 'local':
                    name = strong(name)
                else:
                    name = where + strong(name.split('.')[-1])
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                dump.append('%s&nbsp;= %s' % (name, pydoc.html.repr(value)))
            else:
                dump.append(name + ' <em>undefined</em>')

        rows.append('<tr><td>%s</td></tr>' % small(grey(', '.join(dump))))
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        frames.append('''
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<table width="100%%" cellspacing=0 cellpadding=0 border=0>
%s</table>''' % '\n'.join(rows))
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    exception = ['<p>%s: %s' % (strong(pydoc.html.escape(str(etype))),
                                pydoc.html.escape(str(evalue)))]
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    if type(evalue) is types.InstanceType:
        for name in dir(evalue):
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            if name[:1] == '_': continue
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            value = pydoc.html.repr(getattr(evalue, name))
            exception.append('\n<br>%s%s&nbsp;=\n%s' % (indent, name, value))

    import traceback
    return head + ''.join(frames) + ''.join(exception) + '''
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<!-- The above is a description of an error in a Python program, formatted
     for a Web browser because the 'cgitb' module was enabled.  In case you
     are not reading this in a Web browser, here is the original traceback:
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%s
-->
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''' % ''.join(traceback.format_exception(etype, evalue, etb))
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def text((etype, evalue, etb), context=5):
    """Return a plain text document describing a given traceback."""
    import os, types, time, traceback, linecache, inspect, pydoc

    if type(etype) is types.ClassType:
        etype = etype.__name__
    pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
    date = time.ctime(time.time())
    head = "%s\n%s\n%s\n" % (str(etype), pyver, date) + '''
A problem occurred in a Python script.  Here is the sequence of
function calls leading up to the error, in the order they occurred.
'''

    frames = []
    records = inspect.getinnerframes(etb, context)
    for frame, file, lnum, func, lines, index in records:
        file = file and os.path.abspath(file) or '?'
        args, varargs, varkw, locals = inspect.getargvalues(frame)
        call = ''
        if func != '?':
            call = 'in ' + func + \
                inspect.formatargvalues(args, varargs, varkw, locals,
                    formatvalue=lambda value: '=' + pydoc.text.repr(value))

        highlight = {}
        def reader(lnum=[lnum]):
            highlight[lnum[0]] = 1
            try: return linecache.getline(file, lnum[0])
            finally: lnum[0] += 1
        vars = scanvars(reader, frame, locals)

        rows = [' %s %s' % (file, call)]
        if index is not None:
            i = lnum - index
            for line in lines:
                num = '%5d ' % i
                rows.append(num+line.rstrip())
                i += 1

        done, dump = {}, []
        for name, where, value in vars:
            if name in done: continue
            done[name] = 1
            if value is not __UNDEF__:
                if where == 'global': name = 'global ' + name
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                elif where != 'local': name = where + name.split('.')[-1]
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                dump.append('%s = %s' % (name, pydoc.text.repr(value)))
            else:
                dump.append(name + ' undefined')

        rows.append('\n'.join(dump))
        frames.append('\n%s\n' % '\n'.join(rows))

    exception = ['%s: %s' % (str(etype), str(evalue))]
    if type(evalue) is types.InstanceType:
        for name in dir(evalue):
            value = pydoc.text.repr(getattr(evalue, name))
            exception.append('\n%s%s = %s' % (" "*4, name, value))

    import traceback
    return head + ''.join(frames) + ''.join(exception) + '''

The above is a description of an error in a Python program.  Here is
the original traceback:

%s
''' % ''.join(traceback.format_exception(etype, evalue, etb))
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class Hook:
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    """A hook to replace sys.excepthook that shows tracebacks in HTML."""
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    def __init__(self, display=1, logdir=None, context=5, file=None,
                 format="html"):
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        self.display = display          # send tracebacks to browser if true
        self.logdir = logdir            # log tracebacks to files if not None
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        self.context = context          # number of source code lines per frame
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        self.file = file or sys.stdout  # place to send the output
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        self.format = format
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    def __call__(self, etype, evalue, etb):
        self.handle((etype, evalue, etb))

    def handle(self, info=None):
        info = info or sys.exc_info()
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        if self.format == "html":
            self.file.write(reset())
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        formatter = (self.format=="html") and html or text
        plain = False
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        try:
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            doc = formatter(info, self.context)
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        except:                         # just in case something goes wrong
            import traceback
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            doc = ''.join(traceback.format_exception(*info))
            plain = True
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        if self.display:
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            if plain:
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                doc = doc.replace('&', '&amp;').replace('<', '&lt;')
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                self.file.write('<pre>' + doc + '</pre>\n')
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            else:
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                self.file.write(doc + '\n')
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        else:
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            self.file.write('<p>A problem occurred in a Python script.\n')
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        if self.logdir is not None:
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            import os, tempfile
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            suffix = ['.txt', '.html'][self.format=="html"]
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            (fd, path) = tempfile.mkstemp(suffix=suffix, dir=self.logdir)
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            try:
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                file = os.fdopen(fd, 'w')
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                file.write(doc)
                file.close()
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                msg = '<p> %s contains the description of this error.' % path
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            except:
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                msg = '<p> Tried to save traceback to %s, but failed.' % path
            self.file.write(msg + '\n')
        try:
            self.file.flush()
        except: pass
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handler = Hook().handle
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def enable(display=1, logdir=None, context=5, format="html"):
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    """Install an exception handler that formats tracebacks as HTML.

    The optional argument 'display' can be set to 0 to suppress sending the
    traceback to the browser, and 'logdir' can be set to a directory to cause
    tracebacks to be written to files there."""
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    sys.excepthook = Hook(display=display, logdir=logdir,
                          context=context, format=format)