AttributeError: 'module' object has no attribute 'dumps' due to simplejson dependency

[Jan Beilicke]

At first, thx for the plugin! :)

Unfortunately I cannot get it started in Trac 0.12. After compiling the plugin and setting everything up, I was able to define some basic templates. When trying to create a new ticket, Trac behaves like there is no TracTicketTemplatePlugin installed.

I realized that simplejson is required, so I installed it afterwards. No change.

The trac.log reveals an error:

2011-03-02 09:56:32,863 Trac[main] ERROR: Internal Server Error: 
Traceback (most recent call last):
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 513, in _dispatch_request
    dispatcher.dispatch(req)
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 235, in dispatch
    resp = chosen_handler.process_request(req)
  File "build/bdist.linux-x86_64/egg/tickettemplate/ttadmin.py", line 258, in process_request
    jsonstr = simplejson.dumps(result)
AttributeError: 'module' object has no attribute 'dumps'

Any hint how to solve this issue?

Thx in advance!

[Jan Beilicke]

Issue solved by always loading simplejson:

$ svn diff tickettemplate/ttadmin.py

Index: tickettemplate/ttadmin.py
===================================================================
--- tickettemplate/ttadmin.py   (revision 9909)
+++ tickettemplate/ttadmin.py   (working copy)
@@ -40,10 +40,7 @@
 import textwrap
 import urllib
 
-try: 
-    import json as simplejson 
-except ImportError: 
-    import simplejson 
+import simplejson
 
 from tickettemplate.model import schema, schema_version, TT_Template

The machine still got Python 2.5.2 installed. json should only be available with Python 2.6 (according to the ​Python docs). Side note: I was able to install python-json on the system and it was used somehow:

Python 2.5.2 (r252:60911, Jan 24 2010, 17:44:40) 
[...]
>>> import json
>>> json
<module 'json' from '/usr/lib/python2.5/site-packages/json.pyc'>
>>> json.dumps
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'dumps'
>>>

The ticket can be closed, except you want to address this compatibility issue somehow.

[Steffen Hoffmann]

I've found several json packages non-functional due to this error too.

But after some fiddling with several json variants I've got it to work with just simplejson on Debian 5.0, IIRC. One year later, now on Debian 6.0, this is no longer needed as the Python standard version is not 2.5 but 2.6 and I confirm that json is provided as a standard module now.

All in all this should really be manageable, not a blocker issue. Nevertheless we should enhance the wiki for all the older distributions still around with Python2.4 and 2.5 in production? Only I can't test anymore, since I've not managed to setup (virtual) test environments with that older Python versions.

[Richard Liao]

(In [9957]) Fixed #8555 import json when python above 2.6, otherwise import simplejson

[Steffen Hoffmann]

Awsome response time. Thank you very much for taking care.

[Jan Beilicke]

Replying to richard:

(In [9957]) Fixed #8555 import json when python above 2.6, otherwise import simplejson

Thanks a lot!

[Ryan J Ollos]

In 13633:

0.8: Bump version to 0.8. Added SVN revision to egg. Refs #6589, #6809, #7311, #7404, #7440, #8555, #8609, #9238, #10858.