Wil Tan

Normally, I’m a Django-head, but today I wanted a quick way to write a small web app and have heard good things about web.py so I decided to give it a try. I also wanted minimum fuss to get something up-and-running quickly, and decided to have it served by my existing Apache installation with mod_python.

In the process of setting it up, I ran into a few bumps, and would like to share them:

• My setup is: Python 2.5.2, web.py 0.31, Apache 2.2.8 with mod_python 3.3.1
• The section on configuring mod_python on the web.py installation page doesn’t work for this version. In particular, it tells you to do this:

  main = web.wsgifunc(web.webpyfunc(urls, globals()))
  

  which seems to be the API in web.py 0.2. Using it on 0.3 will land you a nice AttributeError: 'module' object has no attribute 'wsgifunc'. Instead, do this:

  app = web.application(urls, globals(), autoreload=False)
  main = app.wsgifunc()
  

  It’s also worth noting that the version of modpython_gateway.py I’m using is revision 106. With this version, there is no need to place it in the wsgiref package directory since it no longer depend on wsgiref.

• My Apache config is:

    Alias /path /vhosts/dready.org/apps/myapp/
    <Directory /vhosts/dready.org/apps/myapp/>
      Allow from all
  
      <IfModule python_module>
        SetHandler python-program
        PythonHandler modpython_gateway::handler
        PythonOption wsgi.application codep::main
        PythonOption SCRIPT_NAME /path
      </IfModule>
    </Directory>
  

• Notice that I specified the autoreload argument, because the other problem I ran into was that web.py complained the following:

  Traceback (most recent call last):
    File "/usr/local/lib/python2.5/site-packages/web.py-0.31-py2.5.egg/web/application.py", line 209, in process
      return p(lambda: process(processors))
    File "/usr/local/lib/python2.5/site-packages/web.py-0.31-py2.5.egg/web/application.py", line 536, in processor
      h()
    File "/usr/local/lib/python2.5/site-packages/web.py-0.31-py2.5.egg/web/application.py", line 73, in reload_mapping
      mod = __import__(module_name)
  ImportError: No module named _mp_4ba3724007eff4c08a72054c4da2c222
  

  I’m not sure the reason for this, but definitely has something to do with web.py—s auto-reload feature, and the fact that it is running under mod_python so the module name seems to be mangled.

• The other thing is that if you ever run into the problem of getting a file save dialog when requesting the root URL of your app, with the content type of httpd/unix-directory, but not other URLs, this could be due to either Apache or mod_python passing the hint on the request, so if you don’t respond with a Content-Type header (using web.header('Content-Type', 'text/html'), that hint gets copied over to the response.

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This entry was posted on Thursday, January 29th, 2009 at 7:54 pm and is filed under python. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.