Tornado assumes invalid signature for parse_qs on Python 3.1

[holdenweb]

My first install of IPython Notebook on Python 3 (albeit a somewhat venerable one) in a clean virtualenv gave me a stack trace when I tried to access it from the web. The problem arises in tornado/escape.py.

It appears the issue is that neither of the two alternative imports of parse_qs at line 37 (urllib.parse or cgi) make provision for an "encoding" or "errors" keyword argument, which unfortunately parse_qs_bytes is providing both of on line 151.

For the record, removing the arguments to leave line 150 reading

    result = parse_qs(qs, keep_blank_values, strict_parsing)

seems superficially to work, but I have not considered the wider ramifications as I do not currently have either the context or the headspace to do so. The real solution for me is to upgrade my Python 3 to version 3.2 or better, which makes those keyword arguments admissible in urllib.urlparse.parse_qs.

This is on Python 3.1.3, MacOS 10.6.8 with the following pip-installed packages supporting

distribute==0.6.24
ipython==0.13.1
pyzmq==2.2.0.1
tornado==2.4.1
wsgiref==0.1.2

Traceback follows. Feel free to close this issue immediately if you aren't supporting Python 3.1.

(py3)AirHead:~ sholden$ ipython3 notebook
[NotebookApp] Using existing profile dir: '/Users/sholden/.ipython/profile_default'
[NotebookApp] Serving notebooks from /Users/sholden
[NotebookApp] The port 8888 is already in use, trying another random port.
[NotebookApp] The IPython Notebook is running at: http://127.0.0.1:8889/
[NotebookApp] Use Control-C to stop this server and shut down all kernels.
ERROR:root:Uncaught exception, closing connection.
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'
ERROR:root:Exception in callback <zmq.eventloop.stack_context._StackContextWrapper object at 0x1021e0628>
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/zmq/eventloop/ioloop.py", line 440, in _run_callback
callback()
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'
ERROR:root:Uncaught exception, closing connection.
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'
ERROR:root:Exception in callback <zmq.eventloop.stack_context._StackContextWrapper object at 0x1022a5cb0>
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/zmq/eventloop/ioloop.py", line 440, in _run_callback
callback()
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'
ERROR:root:Uncaught exception, closing connection.
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'
ERROR:root:Exception in callback <zmq.eventloop.stack_context._StackContextWrapper object at 0x1022a5e10>
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/zmq/eventloop/ioloop.py", line 440, in _run_callback
callback()
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'
ERROR:root:Uncaught exception, closing connection.
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'
ERROR:root:Exception in callback <zmq.eventloop.stack_context._StackContextWrapper object at 0x1022a5f70>
Traceback (most recent call last):
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/zmq/eventloop/ioloop.py", line 440, in _run_callback
callback()
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/iostream.py", line 311, in wrapper
callback(_args)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 256, in _on_headers
headers=headers, remote_ip=remote_ip)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/httpserver.py", line 391, in init
arguments = parse_qs_bytes(self.query)
File "/Users/sholden/.virtualenvs/py3/lib/python3.1/site-packages/tornado/escape.py", line 151, in parse_qs_bytes
encoding='latin1', errors='strict')
TypeError: parse_qs() got an unexpected keyword argument 'encoding'

[takluyver]

We did support Python 3.1 up to our 0.13 release, I think. But if there's a bug in Tornado, you'll need to contact them. It looks like they don't support 3.1 (here's a previous PR), but if you want to try, that's up to you.

But really, I think you're better off just upgrading Python. Support for Python 3 is improving fast, but all the projects I've seen take 3.2 as the minimum.