1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
"""Handle exceptions in CGI scripts by formatting tracebacks into nice HTML.
To enable this module, do:
import cgitb; cgitb.enable()
at the top of your CGI 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
By default, tracebacks are displayed but not saved, and context is 5.
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()."""
__author__ = 'Ka-Ping Yee'
__version__ = '$Revision$'
import sys
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): return '<small>' + text + '</small>'
def strong(text): return '<strong>' + text + '</strong>'
def grey(text): return '<font color="#909090">' + text + '</font>'
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."""
import tokenize, keyword
vars, lasttoken, parent, prefix = [], None, None, ''
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."""
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 = '<body bgcolor="#f0f0f8">' + pydoc.html.heading(
'<big><big><strong>%s</strong></big></big>' % 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.'''
indent = '<tt>' + small(' ' * 5) + ' </tt>'
frames = []
records = inspect.getinnerframes(etb, context)
for frame, file, lnum, func, lines, index in records:
file = file and os.path.abspath(file) or '?'
link = '<a href="file://%s">%s</a>' % (file, pydoc.html.escape(file))
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)) + ' '
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__:
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('''<p>
<table width="100%%" cellspacing=0 cellpadding=0 border=0>
%s</table>''' % '\n'.join(rows))
exception = ['<p>%s: %s' % (strong(str(etype)), str(evalue))]
if type(evalue) is types.InstanceType:
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))
import traceback
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
-->
''' % ''.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):
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
def __call__(self, etype, evalue, etb):
self.handle((etype, evalue, etb))
def handle(self, info=None):
info = info or sys.exc_info()
self.file.write(reset())
try:
text, doc = 0, html(info, self.context)
except: # just in case something goes wrong
import traceback
text, doc = 1, ''.join(traceback.format_exception(*info))
if self.display:
if text:
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:
import os, tempfile
(fd, path) = tempfile.mkstemp(suffix=['.html', '.txt'][text],
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):
"""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, logdir, context)
|
