| """More comprehensive traceback formatting for Python scripts. | |
| To enable this module, do: | |
| import cgitb; cgitb.enable() | |
| at the top of your script. The optional arguments to enable() are: | |
| display - if true, tracebacks are displayed in the web browser | |
| logdir - if set, tracebacks are written to files in this directory | |
| context - number of lines of source code to show for each stack frame | |
| format - 'text' or 'html' controls the output format | |
| 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) | |
| Alternatively, if you have caught an exception and want cgitb to display it | |
| 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. | |
| """ | |
| import inspect | |
| import keyword | |
| import linecache | |
| import os | |
| import pydoc | |
| import sys | |
| import tempfile | |
| import time | |
| import tokenize | |
| import traceback | |
| import types | |
| def reset(): | |
| """Return a string that resets the CGI and browser to a known state.""" | |
| return '''<!--: spam | |
| Content-Type: text/html | |
| <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> | |
| <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> --> | |
| </font> </font> </font> </script> </object> </blockquote> </pre> | |
| </table> </table> </table> </table> </table> </font> </font> </font>''' | |
| __UNDEF__ = [] # a special sentinel object | |
| def small(text): | |
| if text: | |
| return '<small>' + text + '</small>' | |
| else: | |
| return '' | |
| def strong(text): | |
| if text: | |
| return '<strong>' + text + '</strong>' | |
| else: | |
| return '' | |
| def grey(text): | |
| if text: | |
| return '<font color="#909090">' + text + '</font>' | |
| else: | |
| return '' | |
| 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] | |
| 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) | |
| return None, __UNDEF__ | |
| def scanvars(reader, frame, locals): | |
| """Scan one logical line of Python and look up values of variables used.""" | |
| vars, lasttoken, parent, prefix, value = [], None, None, '', __UNDEF__ | |
| 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(einfo, context=5): | |
| """Return a nice HTML document describing a given traceback.""" | |
| etype, evalue, etb = einfo | |
| if type(etype) is types.ClassType: | |
| etype = etype.__name__ | |
| pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable | |
| date = time.ctime(time.time()) | |
| head = '<body bgcolor="#f0f0f8">' + pydoc.html.heading( | |
| '<big><big>%s</big></big>' % | |
| strong(pydoc.html.escape(str(etype))), | |
| '#ffffff', '#6622aa', pyver + '<br>' + date) + ''' | |
| <p>A problem occurred in a Python script. Here is the sequence of | |
| function calls leading up to the error, in the order they occurred.</p>''' | |
| indent = '<tt>' + small(' ' * 5) + ' </tt>' | |
| frames = [] | |
| records = inspect.getinnerframes(etb, context) | |
| for frame, file, lnum, func, lines, index in records: | |
| if file: | |
| file = os.path.abspath(file) | |
| link = '<a href="file://%s">%s</a>' % (file, pydoc.html.escape(file)) | |
| else: | |
| file = link = '?' | |
| args, varargs, varkw, locals = inspect.getargvalues(frame) | |
| 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> </big>', link, call)] | |
| if index is not None: | |
| i = lnum - index | |
| for line in lines: | |
| num = small(' ' * (5-len(str(i))) + str(i)) + ' ' | |
| if i in highlight: | |
| line = '<tt>=>%s%s</tt>' % (num, pydoc.html.preformat(line)) | |
| rows.append('<tr><td bgcolor="#ffccee">%s</td></tr>' % line) | |
| else: | |
| line = '<tt> %s%s</tt>' % (num, pydoc.html.preformat(line)) | |
| 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__: | |
| if where in ('global', 'builtin'): | |
| name = ('<em>%s</em> ' % where) + strong(name) | |
| elif where == 'local': | |
| name = strong(name) | |
| else: | |
| name = where + strong(name.split('.')[-1]) | |
| dump.append('%s = %s' % (name, pydoc.html.repr(value))) | |
| else: | |
| dump.append(name + ' <em>undefined</em>') | |
| rows.append('<tr><td>%s</td></tr>' % small(grey(', '.join(dump)))) | |
| frames.append(''' | |
| <table width="100%%" cellspacing=0 cellpadding=0 border=0> | |
| %s</table>''' % '\n'.join(rows)) | |
| exception = ['<p>%s: %s' % (strong(pydoc.html.escape(str(etype))), | |
| pydoc.html.escape(str(evalue)))] | |
| if isinstance(evalue, BaseException): | |
| for name in dir(evalue): | |
| if name[:1] == '_': continue | |
| value = pydoc.html.repr(getattr(evalue, name)) | |
| exception.append('\n<br>%s%s =\n%s' % (indent, name, value)) | |
| return head + ''.join(frames) + ''.join(exception) + ''' | |
| <!-- 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: | |
| %s | |
| --> | |
| ''' % pydoc.html.escape( | |
| ''.join(traceback.format_exception(etype, evalue, etb))) | |
| def text(einfo, context=5): | |
| """Return a plain text document describing a given traceback.""" | |
| etype, evalue, etb = einfo | |
| 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 | |
| elif where != 'local': name = where + name.split('.')[-1] | |
| 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 isinstance(evalue, BaseException): | |
| for name in dir(evalue): | |
| value = pydoc.text.repr(getattr(evalue, name)) | |
| exception.append('\n%s%s = %s' % (" "*4, name, value)) | |
| 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)) | |
| class Hook: | |
| """A hook to replace sys.excepthook that shows tracebacks in HTML.""" | |
| def __init__(self, display=1, logdir=None, context=5, file=None, | |
| format="html"): | |
| self.display = display # send tracebacks to browser if true | |
| self.logdir = logdir # log tracebacks to files if not None | |
| self.context = context # number of source code lines per frame | |
| self.file = file or sys.stdout # place to send the output | |
| self.format = format | |
| def __call__(self, etype, evalue, etb): | |
| self.handle((etype, evalue, etb)) | |
| def handle(self, info=None): | |
| info = info or sys.exc_info() | |
| if self.format == "html": | |
| self.file.write(reset()) | |
| formatter = (self.format=="html") and html or text | |
| plain = False | |
| try: | |
| doc = formatter(info, self.context) | |
| except: # just in case something goes wrong | |
| doc = ''.join(traceback.format_exception(*info)) | |
| plain = True | |
| if self.display: | |
| if plain: | |
| doc = doc.replace('&', '&').replace('<', '<') | |
| self.file.write('<pre>' + doc + '</pre>\n') | |
| else: | |
| self.file.write(doc + '\n') | |
| else: | |
| self.file.write('<p>A problem occurred in a Python script.\n') | |
| if self.logdir is not None: | |
| suffix = ['.txt', '.html'][self.format=="html"] | |
| (fd, path) = tempfile.mkstemp(suffix=suffix, dir=self.logdir) | |
| try: | |
| file = os.fdopen(fd, 'w') | |
| file.write(doc) | |
| file.close() | |
| msg = '<p> %s contains the description of this error.' % path | |
| except: | |
| msg = '<p> Tried to save traceback to %s, but failed.' % path | |
| self.file.write(msg + '\n') | |
| try: | |
| self.file.flush() | |
| except: pass | |
| handler = Hook().handle | |
| def enable(display=1, logdir=None, context=5, format="html"): | |
| """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.""" | |
| sys.excepthook = Hook(display=display, logdir=logdir, | |
| context=context, format=format) |