i ran into an interesting bug when writing a json parser(called /home/myusername/py/json.py) in python3
i raised a basic exception and got unexpected output,
when investigating this further i wrote a new script entirely given below
/home/myusername/py/error.py
raise Exception("basic exception")
after running "python3 error.py"
i should get a really short error message, but instead i get console output of the previous run program.
[unexpected debug output of json.py]
[truncated for readability]
[it is extremely long but does not contain further errors]
Traceback (most recent call last):
File "error.py", line 1, in <module>
raise Exception("basic exception")
Exception: basic exception
Error in sys.excepthook:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
from apport.fileutils import likely_packaged, get_recent_crashes
File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
from apport.report import Report
File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
import apport.fileutils
File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
from apport.packaging_impl import impl as packaging
File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 17, in <module>
import json
File "/home/myusername/py/json.py", line 174, in <module>
rs = parser.Object(testcase)
File "/home/myusername/py/json.py", line 104, in Object
raise Exception(self.Array(source, "crashing object scanner"))
Exception: None
Original exception was:
Traceback (most recent call last):
File "error.py", line 1, in <module>
raise Exception("basic exception")
Exception: basic exception
i dont know why i get such a long message. nor do i know why i get debug code of an uncalled script. i would like an explanation, i am running Ubuntu, i have not yet found related bugs on the internet.
it appears that basic exception handling requires a json.py script, so when my error.py raises an exception it loads my json.py script instead of the buildin script, then my json script trows an exception.
the solution is to rename my json.py
Related
I use django-dynamic-model 0.1.0 for dynamic modelling in django.
I have already tried reverting the migrations, changing db. But nothing seems to work.
models.py:
from dynamic_models.models import AbstractModelSchema, AbstractFieldSchema
class ModelSchema(AbstractModelSchema):
pass
class FieldSchema(AbstractFieldSchema):
pass
views.py:
car_model_schema = ModelSchema.objects.create(name='Car')
I face error while creating ModelSchema object:
Internal Server Error: /api/v1.0/boilerplate_apps/graph/
Traceback (most recent call last):
File "/home/ubox72/Extras/graph/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
psycopg2.ProgrammingError: relation "dynamic_models_modelfieldschema" does not exist
LINE 1: ...ynamic_models_modelfieldschema"."max_length" FROM "dynamic_m...
^
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/ubox72/Extras/graph/venv/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner
response = get_response(request)
.......
django.db.utils.ProgrammingError: relation "dynamic_models_modelfieldschema" does not exist
LINE 1: ...ynamic_models_modelfieldschema"."max_length" FROM "dynamic_m...
Trying running this migration as well
python manage.py makemigrations dynamic_models
And then,
python manage.py migrate dynamic_models
This should solve this issue.
Working with Python 3.7.3, still figuring out how exception handling works.
I'm writing an xmpp bot, using slixmpp. I'm trying to make it so that if it loses connection to the server, it will try to reconnect. There doesn't seem to be any way to do this built in to slixmpp, so I'm write something into my own code to do it.
I've imported slixmpp as xmpp, and using it's send_raw() method to test that we're still connected to the server.
while True:
time.sleep(5) # Send every 5 seconds just for testing purposes
xmpp.send_raw('aroo?')
When I sever the connection to the server, this is what it spits out:
Traceback (most recent call last):
File "C:\Program Files\Python37\lib\threading.py", line 917, in _bootstrap_inner
self.run()
File "testcom.py", line 19, in run
eval(self.thing)()
File "testcom.py", line 28, in check_conn
xmpp.send_raw('aroo?')
File "C:\Program Files\Python37\lib\site-packages\slixmpp\xmlstream\xmlstream.py", line 926, in send_raw
raise NotConnectedError
slixmpp.xmlstream.xmlstream.NotConnectedError
I'm assuming that "NotConnectedError" is the exception that I need to catch, so I put the code inside a try block, like so:
try:
while True:
time.sleep(5) # Send every 5 seconds just for testing purposes
xmpp.send_raw('aroo?')
except NotConnectedError:
# Do a thing
pass
And this is what I get:
Traceback (most recent call last):
File "testcom.py", line 28, in check_conn
xmpp.send_raw('aroo?')
File "C:\Program Files\Python37\lib\site-packages\slixmpp\xmlstream\xmlstream.py", line 926, in send_raw
raise NotConnectedError()
slixmpp.xmlstream.xmlstream.NotConnectedError
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Program Files\Python37\lib\threading.py", line 917, in _bootstrap_inner
self.run()
"testcom.py", line 19, in run
eval(self.thing)()
File "testcom.py", line 29, in check_conn
except NotConnectedError:
NameError: name 'NotConnectedError' is not defined
Can anyone tell me what I'm doing wrong here?
Thanks!
I can't see your imports but make sure you have from slixmpp.xmlstream.xmlstream import NotConnectedError otherwise it doesn't have a definition for NotConnectedError within the application. You could also change NotConnectedError to xmpp.xmlstream.xmlstream.NotConnectedError if you don't want to have it imported as well.
I've used pexpect on linux successfully to telnet/ssh into Cisco switches for CLI scrapping. I'm trying to convert this code over to Windows and having some issues since it doesn't support the pxpect.spawn() command.
I read some online documentation and it suggested to use the pexpect.popen_spawn.PopenSpawn command. Can someone please point to me what I'm doing wrong here? I removed all my exception handling to simplify the code. Thanks.
import pexpect
from pexpect.popen_spawn import PopenSpawn
child = pexpect.popen_spawn.PopenSpawn('C:/Windows/System32/telnet 192.168.1.1')
child.expect('Username:')
child.sendline('cisco')
child.expect('Password:')
child.sendline('cisco')
child.expect('>')
child.close()
Error:
Traceback (most recent call last):
File "C:\Users\xxx\AppData\Local\Programs\Python\Python36\lib\site-packages\pexpect\expect.py", line 98, in expect_loop
incoming = spawn.read_nonblocking(spawn.maxread, timeout)
File "C:\Users\xxx\AppData\Local\Programs\Python\Python36\lib\site-packages\pexpect\popen_spawn.py", line 68, in read_nonblocking
raise EOF('End Of File (EOF).')
pexpect.exceptions.EOF: End Of File (EOF).
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Python\windows scripts\telnet\telnet.py", line 37, in <module>
main()
File "C:\Python\windows scripts\telnet\telnet.py", line 20, in main
child.expect('Username:')
File "C:\Users\xxx\AppData\Local\Programs\Python\Python36\lib\site-packages\pexpect\spawnbase.py", line 327, in expect
timeout, searchwindowsize, async_)
File "C:\Users\xxx\AppData\Local\Programs\Python\Python36\lib\site-packages\pexpect\spawnbase.py", line 355, in expect_list
return exp.expect_loop(timeout)
File "C:\Users\xxx\AppData\Local\Programs\Python\Python36\lib\site-packages\pexpect\expect.py", line 104, in expect_loop
return self.eof(e)
File "C:\Users\xxx\AppData\Local\Programs\Python\Python36\lib\site-packages\pexpect\expect.py", line 50, in eof
raise EOF(msg)
pexpect.exceptions.EOF: End Of File (EOF).
<pexpect.popen_spawn.PopenSpawn object at 0x000000000328C550>
searcher: searcher_re:
0: re.compile("b'Username:'")
The solution is to use plink.exe, which is a part of putty installation. You can download it from https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html
Enable TelnetClient on windows system and put plink.exe in the same folder from where you are running pexpect. Then you can telnet using pexpect as mentioned in the below example.
Also, use timeout flag with PopenSpawn to wait for the connection to establish. The above error is due to a timeout flag is not set.
p = pexpect.popen_spawn.PopenSpawn('plink.exe -telnet 192.168.0.1 -P 23', timeout=1)
I have pure project on CherryPy and want AuthTool to use bcrypt module for password processing.
But when I put "import bcrypt" line into AuthTool.py the CherryPy tells me:
[17/Nov/2017:17:55:57] ENGINE Error in background task thread function <bound method Autoreloader.run of <cherrypy.process.plugins.Autoreloader object at 0x0000026948C82E80>>.
AttributeError: cffi library '_bcrypt' has no function, constant or global variable named '__loader__'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "C:\Users\Serge\AppData\Local\Programs\Python\Python36\lib\site-packages\cherrypy\process\plugins.py", line 519, in run
self.function(*self.args, **self.kwargs)
File "C:\Users\Serge\AppData\Local\Programs\Python\Python36\lib\site-packages\cherrypy\process\plugins.py", line 651, in run
for filename in self.sysfiles() | self.files:
File "C:\Users\Serge\AppData\Local\Programs\Python\Python36\lib\site-packages\cherrypy\process\plugins.py", line 635, in sysfiles
hasattr(m, '__loader__') and
SystemError: <built-in function hasattr> returned a result with an error set
Exception in thread Autoreloader:
AttributeError: cffi library '_bcrypt' has no function, constant or global variable named '__loader__'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "C:\Users\Serge\AppData\Local\Programs\Python\Python36\lib\threading.py", line 916, in _bootstrap_inner
self.run()
File "C:\Users\Serge\AppData\Local\Programs\Python\Python36\lib\site-packages\cherrypy\process\plugins.py", line 519, in run
self.function(*self.args, **self.kwargs)
File "C:\Users\Serge\AppData\Local\Programs\Python\Python36\lib\site-packages\cherrypy\process\plugins.py", line 651, in run
for filename in self.sysfiles() | self.files:
File "C:\Users\Serge\AppData\Local\Programs\Python\Python36\lib\site-packages\cherrypy\process\plugins.py", line 635, in sysfiles
hasattr(m, '__loader__') and
SystemError: <built-in function hasattr> returned a result with an error set
After that everithing works fine but Autoloader. I have bcrypt (3.1.4) and CherryPy (11.1.0).
Can I do something to fix this issue this autoreloader? Merci.
You could disable the autoloader. Set 'engine.autoloader.on' to False. Of course you will loose auto loading when monitored files are changed and thus you'll need to manually restart the server on each change. Another way would be to put the server in production mode. See available mode and what they do at: http://docs.cherrypy.org/en/latest/config.html#id14
BTW: I am seeing a similar issue with cherrypy (13.0.0) and cryptography (2.1.4)
I have a rather simple, naive Python/WSGI/Pyramid web-server.
It's run using wsgiref.simple_server.make_server(), on a server built using pyramid.config.Configurator().make_wsgi_app(). This server works fine.
However, the application it's serving has a lot of javascript image mouseover popups. If you run the mouse across the page, it can generate 20+ image requests. This is fine as well (It's an internal thing, not a lot of users).
However, doing so causes the server to emit something like half a dozen error tracebacks:
10.1.1.4 - - [25/Apr/2014 01:56:42] "GET /*SNIP* 500 59
----------------------------------------
Exception happened during processing of request from ('10.1.1.4', 18338)
Traceback (most recent call last):
File "/usr/lib/python3.4/wsgiref/handlers.py", line 138, in run
self.finish_response()
File "/usr/lib/python3.4/wsgiref/handlers.py", line 180, in finish_response
self.write(data)
File "/usr/lib/python3.4/wsgiref/handlers.py", line 274, in write
self.send_headers()
File "/usr/lib/python3.4/wsgiref/handlers.py", line 333, in send_headers
self._write(bytes(self.headers))
File "/usr/lib/python3.4/wsgiref/handlers.py", line 453, in _write
self.stdout.write(data)
File "/usr/lib/python3.4/socket.py", line 391, in write
return self._sock.send(b)
BrokenPipeError: [Errno 32] Broken pipe
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.4/wsgiref/handlers.py", line 141, in run
self.handle_error()
File "/usr/lib/python3.4/wsgiref/handlers.py", line 368, in handle_error
self.finish_response()
File "/usr/lib/python3.4/wsgiref/handlers.py", line 180, in finish_response
self.write(data)
File "/usr/lib/python3.4/wsgiref/handlers.py", line 274, in write
self.send_headers()
File "/usr/lib/python3.4/wsgiref/handlers.py", line 331, in send_headers
if not self.origin_server or self.client_is_modern():
File "/usr/lib/python3.4/wsgiref/handlers.py", line 344, in client_is_modern
return self.environ['SERVER_PROTOCOL'].upper() != 'HTTP/0.9'
TypeError: 'NoneType' object is not subscriptable
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.4/socketserver.py", line 306, in _handle_request_noblock
self.process_request(request, client_address)
File "/usr/lib/python3.4/socketserver.py", line 332, in process_request
self.finish_request(request, client_address)
File "/usr/lib/python3.4/socketserver.py", line 345, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib/python3.4/socketserver.py", line 666, in __init__
self.handle()
File "/usr/lib/python3.4/wsgiref/simple_server.py", line 126, in handle
handler.run(self.server.get_app())
File "/usr/lib/python3.4/wsgiref/handlers.py", line 144, in run
self.close()
File "/usr/lib/python3.4/wsgiref/simple_server.py", line 35, in close
self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
I understand why I'm getting broken pipe errors (the request for the image is canceled before the image has fully transfered, because the mouseover popup has closed), and it seems harmless.
However, I have no idea how to silence this traceback. There are thousands of them in my logs, and it makes debugging actual errors a nightmare. I don't care that I'm getting broken pipe errors, how can I catch them and swallow them silently?
It seems like wsgiref.simple_server.make_server() installs an internal handler that catches BrokenPipeError: [Errno 32] Broken pipe, prints the traceback, and then swallows the error. I've tried wrapping the run_server() call in a try-except clause, and it doesn't have any effect.
I wound up just switching to using the CherryPy WSGI Server. It doesn't suffer from the broken pipe log issues, and is probably far more robust as well.
It also uses a threadpool, so it's more performant as well (multiple requests aren't blocking!).
I didn't find a straightforward way for achieving this, however, you can always do some monkey patching:
from wsgiref.handlers import BaseHandler
import sys
def ignore_broken_pipes(self):
if sys.exc_info()[0] != BrokenPipeError: BaseHandler.__handle_error_original_(self)
BaseHandler.__handle_error_original_ = BaseHandler.handle_error
BaseHandler.handle_error = ignore_broken_pipes
You will not see these annoyances after running this code somewhere in the beginning anymore.
For me, it looks like a bug somewhere in wsgiref implementation of BaseHandler:
def handle_error(self):
"""Log current error, and send error output to client if possible"""
self.log_exception(sys.exc_info())
if not self.headers_sent:
self.result = self.error_output(self.environ, self.start_response)
self.finish_response()
# XXX else: attempt advanced recovery techniques for HTML or text?
if BrokenPipeError is handled by this method, finish_response crashes. Why do we ever want to finish response if pipe is broken? Where the data is sent to?